/*
Using the Script
The script contains several functions, discussed in detail below. The first three functions set styles, 
allowing you to discriminate between elements based on their ID, their CLASS, or their tag name. 
The second set of functions simply allows you to get the current style settings for each element.

The simplest of these is setStyleById(), which takes an element ID, a CSS property, and a value, 
and sets that element’s property to that value.

setStyleById(ID, property, value)
The second function takes a tag name (e.g., H1), a class name, a CSS property, and a value, 
and sets the style for all elements of that type (or for all elements, if passed the “*” specifier).

setStyleByClass(type, class, property, value)
The third function takes a tag name (e.g., H1), 
a CSS property, a value, and the final (and optional) Boolean argument, which specifies whether 
to modify the style for that element in the stylesheet or in the .style array of the element. 
Unfortunately, due to the lack of a functional selectorText property in Netscape6/Mozilla, 
the stylesheet mode of the function does not work.

setStyleByTag(tagname, property, value, global)
The second set of functions allows you to read 
the values of any CSS property for any element, based on the element name, ID, or CLASS selector, 
as above.

getStyleById(ID, property)
getStyleByClass(type, class, property)
getStyleByTag(type, property)


If the property is found, it is returned as a string. If not, the functions return null.


*/
var ugly_selectorText_workaround_flag = false;
var allStyleRules;
// code developed using the following workaround (CVS v1.15) as an example.
// http://lxr.mozilla.org/seamonkey/source/extensions/xmlterm/ui/content/XMLTermCommands.js
function ugly_selectorText_workaround() {
	if((navigator.userAgent.indexOf("Gecko") == -1) ||
	   (ugly_selectorText_workaround_flag)) {
		return; // we've already been here or shouldn't be here
	}
	var styleElements = document.getElementsByTagName("style");
	
	for(var i = 0; i < styleElements.length; i++) {
		var styleText = styleElements[i].firstChild.data;
		// this should be using match(/\b[\w-.]+(?=\s*\{)/g but ?= causes an
		// error in IE5, so we include the open brace and then strip it
		allStyleRules = styleText.match(/\b[\w-.]+(\s*\{)/g);
	}

	for(var i = 0; i < allStyleRules.length; i++) {
		// probably insufficient for people who like random gobs of 
		// whitespace in their styles
		allStyleRules[i] = allStyleRules[i].substr(0, (allStyleRules[i].length - 2));
	}
	ugly_selectorText_workaround_flag = true;
}


// setStyleById: given an element id, style property and 
// value, apply the style.
// args:
//  i - element id
//  p - property
//  v - value
//
function setStyleById(i, p, v) {
	var n = document.getElementById(i);
	n.style[p] = v;
}

// getStyleById: given an element ID and style property
// return the current setting for that property, or null.
// args:
//  i - element id
//  p - property
function getStyleById(i, p) {
	var n = document.getElementById(i);
	var s = eval("n.style." + p);

	// try inline
	if((s != "") && (s != null)) {
		return s;
	}

	// try currentStyle
	if(n.currentStyle) {
		var s = eval("n.currentStyle." + p);
		if((s != "") && (s != null)) {
			return s;
		}
	}
	
	// try styleSheets
	var sheets = document.styleSheets;
	if(sheets.length > 0) {
		// loop over each sheet
		for(var x = 0; x < sheets.length; x++) {
			// grab stylesheet rules
			var rules = sheets[x].cssRules;
			if(rules.length > 0) {
				// check each rule
				for(var y = 0; y < rules.length; y++) {
					var z = rules[y].style;
					// selectorText broken in NS 6/Mozilla: see
					// http://bugzilla.mozilla.org/show_bug.cgi?id=51944
					ugly_selectorText_workaround();
					if(allStyleRules) {
						if(allStyleRules[y] == i) {
							return z[p];
						}			
					} else {
						// use the native selectorText and style stuff
						if(((z[p] != "") && (z[p] != null)) ||
						   (rules[y].selectorText == i)) {
							return z[p];
						}
					}
				}
			}
		}
	}
	return null;
}

// setStyleByClass: given an element type and a class selector,
// style property and value, apply the style.
// args:
//  t - type of tag to check for (e.g., SPAN)
//  c - class name
//  p - CSS property
//  v - value
var ie = (document.all) ? true : false;

function setStyleByClass(t,c,p,v){
	var elements;
	if(t == '*') {
		// '*' not supported by IE/Win 5.5 and below
		elements = (ie) ? document.all : document.getElementsByTagName('*');
	} else {
		elements = document.getElementsByTagName(t);
	}
	for(var i = 0; i < elements.length; i++){
		var node = elements.item(i);
		for(var j = 0; j < node.attributes.length; j++) {
			if(node.attributes.item(j).nodeName == 'class') {
				if(node.attributes.item(j).nodeValue == c) {
					eval('node.style.' + p + " = '" +v + "'");
				}
			}
		}
	}
}

// getStyleByClass: given an element type, a class selector and a property,
// return the value of the property for that element type.
// args:
//  t - element type
//  c - class identifier
//  p - CSS property
function getStyleByClass(t, c, p) {
	// first loop over elements, because if they've been modified they
	// will contain style data more recent than that in the stylesheet
	var elements;
	if(t == '*') {
		// '*' not supported by IE/Win 5.5 and below
		elements = (ie) ? document.all : document.getElementsByTagName('*');
	} else {
		elements = document.getElementsByTagName(t);
	}
	for(var i = 0; i < elements.length; i++){
		var node = elements.item(i);
		for(var j = 0; j < node.attributes.length; j++) {
			if(node.attributes.item(j).nodeName == 'class') {
				if(node.attributes.item(j).nodeValue == c) {
					var theStyle = eval('node.style.' + p);
					if((theStyle != "") && (theStyle != null)) {
						return theStyle;
					}
				}
			}
		}		
	}
	// if we got here it's because we didn't find anything
	// try styleSheets
	var sheets = document.styleSheets;
	if(sheets.length > 0) {
		// loop over each sheet
		for(var x = 0; x < sheets.length; x++) {
			// grab stylesheet rules
			var rules = sheets[x].cssRules;
			if(rules.length > 0) {
				// check each rule
				for(var y = 0; y < rules.length; y++) {
					var z = rules[y].style;
					// selectorText broken in NS 6/Mozilla: see
					// http://bugzilla.mozilla.org/show_bug.cgi?id=51944
					ugly_selectorText_workaround();
					if(allStyleRules) {
						if((allStyleRules[y] == c) ||
						   (allStyleRules[y] == (t + "." + c))) {
							return z[p];
						}			
					} else {
						// use the native selectorText and style stuff
						if(((z[p] != "") && (z[p] != null)) &&
						   ((rules[y].selectorText == c) ||
						    (rules[y].selectorText == (t + "." + c)))) {
							return z[p];
						}
					}
				}
			}
		}
	}

	return null;
}

// setStyleByTag: given an element type, style property and 
// value, and whether the property should override inline styles or
// just global stylesheet preferences, apply the style.
// args:
//  e - element type or id
//  p - property
//  v - value
//  g - boolean 0: modify global only; 1: modify all elements in document
function setStyleByTag(e, p, v, g) {
	if(g) {
		var elements = document.getElementsByTagName(e);
		for(var i = 0; i < elements.length; i++) {
			elements.item(i).style[p] = v;
		}
	} else {
		var sheets = document.styleSheets;
		if(sheets.length > 0) {
			for(var i = 0; i < sheets.length; i++) {
				var rules = sheets[i].cssRules;
				if(rules.length > 0) {
					for(var j = 0; j < rules.length; j++) {
						var s = rules[j].style;
						// selectorText broken in NS 6/Mozilla: see
						// http://bugzilla.mozilla.org/show_bug.cgi?id=51944
						ugly_selectorText_workaround();
						if(allStyleRules) {
							if(allStyleRules[j] == e) {
								s[p] = v;
							}			
						} else {
							// use the native selectorText and style stuff
							if(((s[p] != "") && (s[p] != null)) &&
							   (rules[j].selectorText == e)) {
								s[p] = v;
							}
						}

					}
				}
			}
		}
	}
}

// getStyleByTag: given an element type and style property, return
// the property's value
// args:
//  e - element type
//  p - property
function getStyleByTag(e, p) {
	var sheets = document.styleSheets;
	if(sheets.length > 0) {
		for(var i = 0; i < sheets.length; i++) {
			var rules = sheets[i].cssRules;
			if(rules.length > 0) {
				for(var j = 0; j < rules.length; j++) {
					var s = rules[j].style;
					// selectorText broken in NS 6/Mozilla: see
					// http://bugzilla.mozilla.org/show_bug.cgi?id=51944
					ugly_selectorText_workaround();
					if(allStyleRules) {
						if(allStyleRules[j] == e) {
							return s[p];
						}			
					} else {
						// use the native selectorText and style stuff
						if(((s[p] != "") && (s[p] != null)) &&
						   (rules[j].selectorText == e)) {
							return s[p];
						}
					}

				}
			}
		}
	}


	// if we don't find any style sheets, return the value for the first
	// element of this type we encounter without a CLASS or STYLE attribute
	var elements = document.getElementsByTagName(e);
	var sawClassOrStyleAttribute = false;
	for(var i = 0; i < elements.length; i++) {
		var node = elements.item(i);
		for(var j = 0; j < node.attributes.length; j++) {
			if((node.attributes.item(j).nodeName == 'class') ||
			   (node.attributes.item(j).nodeName == 'style')){
			   sawClassOrStyleAttribute = true;
			}
		}
		if(! sawClassOrStyleAttribute) {
			return elements.item(i).style[p];
		}
	}
}