//function to change ifrmae src:
function goToSrc(page) {
	iframe = document.getElementById("contentIframe");
	iframe.src = page+".html";
	//ok, now let's change the content div background image:
	document.getElementById("motherDiv").style.backgroundImage = "url("+page+".jpg)";
	//contentDiv.style.backgroundImage = "url("+page+".jpg)";
}

<!--
function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
	d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
	if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
	for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
	if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->
<!--
function MM_goToURL() { //v3.0
var i, args=MM_goToURL.arguments; document.MM_returnValue = false;
for (i=0; i<(args.length-1); i+=2) eval(args[i]+".location='"+args[i+1]+"'");
}
//-->
function loadBackground(page)
{
	alert('1');
	document.getElementById("motherDiv").style.backgroundImage = "url("+page+".jpg)";
}
/////
// (C) 2000 www.CodeLifter.com
// http://www.codelifter.com
// Free for all users, but leave in this  header
// NS4-6,IE4-6
// Fade effect only in IE; degrades gracefully
// =======================================
// set the following variables
// =======================================
// Set slideShowSpeed (milliseconds)
var slideShowSpeed = 3000
// Duration of crossfade (seconds)
var crossFadeDuration = 3
// Specify the image files
var Pic = new Array() // don't touch this
// to add more images, just continue
// the pattern, adding to the array below
Pic[0] = 'images/mainpage_pics_1.jpg'
Pic[1] = 'images/defil/2.jpg'
Pic[2] = 'images/defil/3.jpg'
Pic[3] = 'images/defil/4.jpg'
Pic[4] = 'images/defil/5.jpg'
Pic[5] = 'images/defil/6.jpg'
//
// =======================================
// do not edit anything below this line
// =======================================
var t
var j = 0
var p = Pic.length
//
var preLoad = new Array()
for (i = 0; i < p; i++){
	preLoad[i] = new Image()
	preLoad[i].src = Pic[i]
}
//
function runSlideShow(){
	if (document.all){
		document.images.SlideShow.style.filter="blendTrans(duration=2)"
		document.images.SlideShow.style.filter="blendTrans(duration=crossFadeDuration)"
		document.images.SlideShow.filters.blendTrans.Apply()
	}
	document.images.SlideShow.src = preLoad[j].src
	if (document.all){
		document.images.SlideShow.filters.blendTrans.Play()
	}
	j = j + 1
	if (j > (p-1)) j=0
	t = setTimeout('runSlideShow()', slideShowSpeed)
}
//
function openwindow(url,width,height,scrollbars)
{
	window.open(url,"mywindow","menubar=0,resizable=0,width="+width+",height="+height+",scrollbars="+scrollbars);
}
//
function validateEmail(str) {
	//
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.indexOf(at,(lat+1))!=-1){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.indexOf(dot,(lat+2))==-1){
		//alert("Invalid E-mail ID")
		return false
	}

	if (str.indexOf(" ")!=-1){
		//alert("Invalid E-mail ID")
		return false
	}

	return true
}