function lib_bwcheck(){
	var bw = new Object();
	bw.ver=navigator.appVersion;
	bw.agent=navigator.userAgent;
	bw.dom=document.getElementById?1:0;
	bw.win=bw.agent.indexOf("Win")>-1;
	bw.operaOld=((!bw.dom)&&bw.agent.indexOf("Opera")>-1);
	bw.opera5=bw.agent.indexOf("Opera 5")>-1;
	bw.opera5=bw.agent.indexOf("Opera/5")>-1;
	bw.opera6=bw.agent.indexOf("Opera 6")>-1;
	bw.opera6=bw.agent.indexOf("Opera/6")>-1;
	bw.operaM=(bw.opera5||bw.opera6);	
	bw.opera7p=(!bw.operaOld)&&(!bw.operaM)&&(bw.agent.indexOf("Opera")>-1);
	bw.opera=(bw.opera5||bw.opera6||bw.opera7p);
	bw.ie5=(bw.ver.indexOf("MSIE 5")>-1 && bw.dom && !bw.opera)?1:0; 
	bw.ie5_5=(bw.ver.indexOf("MSIE 5.5")>-1 && bw.dom && !bw.opera)?1:0; 	
	bw.ie6=(bw.ver.indexOf("MSIE 6")>-1 && bw.dom && !bw.opera)?1:0;
	bw.ie7=(bw.ver.indexOf("MSIE 7")>-1 && bw.dom && !bw.opera)?1:0;
	bw.ie4=(document.all && !bw.dom && !bw.opera5)?1:0;
	bw.ie6p=(bw.dom && (bw.ver.indexOf("MSIE")>-1))?1:0 
	bw.ie=bw.ie4||bw.ie5||bw.ie6||bw.ie6p||bw.ie7;
	bw.mac=bw.agent.indexOf("Mac")>-1;
	bw.ns6=(bw.dom && parseInt(bw.ver) >= 5 &&!bw.opera) ?1:0;
	bw.ns6p = bw.ns6; 
	bw.ns4=(document.layers && !bw.dom)?1:0;
	bw.bw=(bw.ie7 || bw.ie6 || bw.ie5 || bw.ie5_5  || bw.ns6 || bw.opera);
	return bw;
}
var bw = lib_bwcheck();

// fct pseudodreamweaver

var tabImg = new Array();

function preloadImg() {
	preload("img");
}

function preload(tag) { 
  var elements = document.getElementsByTagName(tag);
  var objA;
  
  for (i=0;i<elements.length;i++) {
  	if (elements[i].src) {
	  	if (regExpPatternImgOff.test(elements[i].src)) {
	  		tabImg[i] = new Image();
	  		tabImg[i].src = elements[i].src.replace(regExpPatternImgOff, patternImgOn);
			if (!regExpImgMenu.test(elements[i].id)) {
				objA = chercheElementParent("a", elements[i]);	
				if (bw.ie && !bw.opera) {
					elements[i].onmouseover=swap;
					elements[i].onmouseout=restore;	
					if (objA) {
						objA.onfocus=swapChildImg;
						objA.onblur=restoreChildImg;			
					}
				} else  {
					elements[i].setAttribute("onmouseover", "swap(this)");	
					elements[i].setAttribute("onmouseout", "restore(this)");	
					if(objA) {
						objA.setAttribute("onfocus", "swapChildImg(this)");	
						objA.setAttribute("onblur", "restoreChildImg(this)");				
					}
				}	
			}
	  	}
	  }	
  }
} 
// fonction pour mouseover sur images
function swap(imgSwpObj) {
	if (imgSwpObj) {
		imgSwpObj.src = imgSwpObj.src.replace(regExpPatternImgOff, patternImgOn);
	} else {
		if (this) swap(this); 
	}
}

function restore(imgSwpObj) {
	if (imgSwpObj) {
		imgSwpObj.src = imgSwpObj.src.replace(regExpPatternImgOn, patternImgOff);
	} else {
		if (this) restore(this); 	
	}
}

function swapChildImg(aSwpObj) {
	var imgSwpObj;
	if (aSwpObj) {
		imgSwpObj = chercheElementEnfant("img", aSwpObj);
		swap(imgSwpObj);
	} else {
		if (this) swapChildImg(this); 
	}
}

function restoreChildImg(aSwpObj) {
	var imgSwpObj;
	if (aSwpObj) {
		imgSwpObj = chercheElementEnfant("img", aSwpObj);
		restore(imgSwpObj);
	} else {
		if (this) restoreChildImg(this); 
	}
}

var regExpPatternImgOff;
var regExpPatternImgOn;
var patternImgOn;
var patternImgOff;

function setPatternImgOver(patternOff, patternOn) {
	regExpPatternImgOff = new RegExp(patternOff);
	regExpPatternImgOn = new RegExp(patternOn);	
	patternImgOn = patternOn;
	patternImgOff = patternOff;	
}

setPatternImgOver("_0", "_1"); // pattern des url des images ayant un mouseover et devant etre preloadée
regExpImgMenu = new RegExp("^im"); // pattern des id des images faisant parties d'un menu

// les recherches se font sur un seul niveau, pas de recursivite pour questions de perf

function chercheElementParent(nomElement, domObj) {
	var objCourant = domObj.parentNode;
	// on essai juste avec le premier
	if (objCourant.nodeName.toLowerCase() == nomElement.toLowerCase()) return objCourant;
	else return false;	
}

function chercheElementEnfant(nomElement, domObj) {
	var objEnfants = domObj.childNodes;
	var objRech = false;
	for (i=0;i<objEnfants.length;i++) {
	   if (objEnfants[i].nodeType==1) {
			if (objEnfants[i].nodeName.toLowerCase() == nomElement.toLowerCase()) {
				objRech = objEnfants[i];
			}
		}
	}	
	return objRech;	
}