/* function checkForText                                                      */
/* Check for content (text or an image) in an html element                    */
/*                                                                            */
/* Parameters:                                                                */
/*  Object objectToCheck - the elementID to check                             */
/*  Object objectToShow - the elementID to show                               */
/*  [Optional] String display - blank or null if not changing display,        */
/*               otherwise a valid display type (e.g. block or inline)        */
/*  [Optional] String visible - true if object's visibility should be set to  */
/*               visible                                                      */

function checkForText(objectToCheck, objectToShow, display, visible) {
  if (recursiveTextCheck(document.getElementById(objectToCheck))) {    
    if (display != "" && display != null)
      document.getElementById(objectToShow).style.display = checkDisplay(display); //Make objectToShow display
    
    if (visible != "" || visible != null)
      document.getElementById(objectToShow).style.visibility = visible; //Make objectToShow visible
  }
}


//recursive helper function

function recursiveTextCheck(objectName) {
  var i;

  for (i = 0; i < objectName.childNodes.length; i++) {
    if (objectName.childNodes[i].nodeType == 1) { //Element node
      if (objectName.childNodes[i].nodeName == "IMG")
        return true;
        
      if (recursiveTextCheck(objectName.childNodes[i])) //Recursive jump into element
        return true;
    }
    else if (objectName.childNodes[i].nodeType == 3) { //Text node
      if (objectName.childNodes[i].nodeValue.search(/\S/) != -1)
        return true;
    }
  }
  
  return false;
}


//handle poor css support in certain browsers

function checkDisplay(display) {
  if (display.search("table") != -1) {
    if (BrowserDetect.browser == "Explorer")
      return "block";
    
    return display;
  }
  
  return display;
}


//from http://www.quirksmode.org/js/detect.html

var BrowserDetect = {
	init: function () {
		this.browser = this.searchString(this.dataBrowser) || "An unknown browser";
		this.version = this.searchVersion(navigator.userAgent)
			|| this.searchVersion(navigator.appVersion)
			|| "an unknown version";
		this.OS = this.searchString(this.dataOS) || "an unknown OS";
	},
	searchString: function (data) {
		for (var i=0;i<data.length;i++)	{
			var dataString = data[i].string;
			var dataProp = data[i].prop;
			this.versionSearchString = data[i].versionSearch || data[i].identity;
			if (dataString) {
				if (dataString.indexOf(data[i].subString) != -1)
					return data[i].identity;
			}
			else if (dataProp)
				return data[i].identity;
		}
	},
	searchVersion: function (dataString) {
		var index = dataString.indexOf(this.versionSearchString);
		if (index == -1) return;
		return parseFloat(dataString.substring(index+this.versionSearchString.length+1));
	},
	dataBrowser: [
		{ 	string: navigator.userAgent,
			subString: "OmniWeb",
			versionSearch: "OmniWeb/",
			identity: "OmniWeb"
		},
		{
			string: navigator.vendor,
			subString: "Apple",
			identity: "Safari"
		},
		{
			prop: window.opera,
			identity: "Opera"
		},
		{
			string: navigator.vendor,
			subString: "iCab",
			identity: "iCab"
		},
		{
			string: navigator.vendor,
			subString: "KDE",
			identity: "Konqueror"
		},
		{
			string: navigator.userAgent,
			subString: "Firefox",
			identity: "Firefox"
		},
		{
			string: navigator.vendor,
			subString: "Camino",
			identity: "Camino"
		},
		{		// for newer Netscapes (6+)
			string: navigator.userAgent,
			subString: "Netscape",
			identity: "Netscape"
		},
		{
			string: navigator.userAgent,
			subString: "MSIE",
			identity: "Explorer",
			versionSearch: "MSIE"
		},
		{
			string: navigator.userAgent,
			subString: "Gecko",
			identity: "Mozilla",
			versionSearch: "rv"
		},
		{ 		// for older Netscapes (4-)
			string: navigator.userAgent,
			subString: "Mozilla",
			identity: "Netscape",
			versionSearch: "Mozilla"
		}
	],
	dataOS : [
		{
			string: navigator.platform,
			subString: "Win",
			identity: "Windows"
		},
		{
			string: navigator.platform,
			subString: "Mac",
			identity: "Mac"
		},
		{
			string: navigator.platform,
			subString: "Linux",
			identity: "Linux"
		}
	]

};
BrowserDetect.init();