var browser = "";
var version = "";
var browseWidth;
var browseHeight;
var browserok = false;


function checkBrowser() {

	var appname = navigator.appName;
	var useragent = navigator.userAgent;	
	var checkpassed = false;
	
	
	if (useragent.indexOf("Opera")!=-1) {
  		browser="Opera";
  		versionindex=navigator.userAgent.indexOf("Opera")+6;
		if (parseInt(navigator.userAgent.charAt(versionindex))>=8) {
			version="8";
		}
	} else if (useragent.indexOf("MSIE")!=-1) {
  		browser="Microsoft";
  		temp=navigator.appVersion.split("MSIE");
		version=parseFloat(temp[1]);

  	} else if (useragent.indexOf("Firefox")!=-1) {
  		browser="Firefox";
  		versionindex=navigator.userAgent.indexOf("Firefox")+8;
		if (parseInt(navigator.userAgent.charAt(versionindex))>=1) {
			version="1";
		}
	} else if (useragent.indexOf("Netscape")!=-1) {
  		browser="Netscape";
  		versionindex=navigator.userAgent.indexOf("Netscape")+9;
		if (parseInt(navigator.userAgent.charAt(versionindex))>=6) {
			version="6";
		}
		
 	} else {
	   //browser is unknown;
	   browserok = false;
	   return;
	}
 	browserok = true;
	//now check screen resolution
	checkScreenSize();
 
 }
 
 function checkScreenSize() {
   	scr_w = screen.availWidth;
	scr_h = screen.availHeight;
	

	if ((browser.indexOf("Firefox")!=-1) || (browser.indexOf("Netscape")!=-1)){
   		browseWidth=window.innerWidth;
  		 browseHeight=window.innerHeight;
	}
	if (browser.indexOf("Microsoft")!=-1){
  		browseWidth=document.body.clientWidth;
   		browseHeight=document.body.clientHeight;
	}
	if (browser.indexOf("Opera")!=-1){
  		browseWidth=document.body.clientWidth;
   		browseHeight=document.body.clientHeight;
	}
	

}

function fadein(iteration) {
  //This function takes an object and fades it to full opacity
  //first perform browsercheck
  checkBrowser();
  	if(browserok) {
 		timer=setInterval("doFade("+iteration+")",30);
 	} else {
		document.getElementById("heading").style.visibility="visible";
		document.getElementById("subheading").style.visibility="visible";
		document.getElementById("slogan").style.visibility="visible";
	}

}


function doFade(iteration) {
  	
 	if (browser.indexOf("Microsoft")!=-1) {
  		document.getElementById("image"+iteration).filters.alpha.opacity+=2;
  		if (document.getElementById("image"+iteration).filters.alpha.opacity==100) {
    		clearInterval(timer);
    		iteration+=1;
    		if (iteration < 4) {
    			fadein(iteration);
    			if (iteration==2) {
					document.getElementById("heading").style.visibility="visible";
					document.getElementById("subheading").style.visibility="visible";
				} 
    		}
    		if (iteration==4) {
					document.getElementById("slogan").style.visibility="visible";
			}
		} 
	} else if ((browser.indexOf("Firefox")!=-1)||(browser.indexOf("Netscape")!=-1)) {
		currentopacity = Number(document.getElementById("image"+iteration).style.MozOpacity)+0.02;
	  	document.getElementById("image"+iteration).style.MozOpacity=String(currentopacity);
  		if (currentopacity==1) {
    		clearInterval(timer);
    		iteration+=1;
    		if (iteration < 4) {
    			fadein(iteration);
				if (iteration==2) {
					document.getElementById("heading").style.visibility="visible";
					document.getElementById("subheading").style.visibility="visible";
				} 
    		}
    		if (iteration==4) {
					document.getElementById("slogan").style.visibility="visible";
				}
  	}
 	} else {
	 	//all other browsers
 		document.getElementById("heading").style.visibility="visible";
		document.getElementById("subheading").style.visibility="visible";
		document.getElementById("slogan").style.visibility="visible";
	}
}