var src_bg  = "fileadmin/img_backgrounds/";
var src_btn = "fileadmin/img_buttons/";

imageinf			= new Image();
imageinf.src			= src_bg + "main_inf.jpg";

infbutton			= new Image();
infbutton.src			= src_btn + "main_inf_1.gif";
infbuttonover			= new Image();
infbuttonover.src		= src_btn + "main_inf_2.gif";

imageidm			= new Image();
imageidm.src			= src_bg + "main_idm.jpg";

idmbutton			= new Image();
idmbutton.src			= src_btn + "main_idm_1.gif";
idmbuttonover			= new Image();
idmbuttonover.src		= src_btn + "main_idm_2.gif";

imageweb			= new Image();
imageweb.src			= src_bg + "main_web.gif";

webbutton			= new Image();
webbutton.src			= src_btn + "main_web_1.gif";
webbuttonover			= new Image();
webbuttonover.src		= src_btn + "main_web_2.gif";

imagesus			= new Image();
imagesus.src			= src_bg + "main_service.jpg";

susbutton			= new Image();
susbutton.src			= src_btn + "main_service_1.gif";
susbuttonover			= new Image();
susbuttonover.src		= src_btn + "main_services_2.gif";

fadefinished = true;

function opacity(id, opacStart, opacEnd, millisec) { 
    //speed for each frame 
    var speed = Math.round(millisec / 100); 
    var timer = 0; 

    //determine the direction for the blending, if start and end are the same nothing happens 
    if(opacStart > opacEnd) { 
        for(i = opacStart; i >= opacEnd; i--) { 
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            timer++; 
        } 
    } else if(opacStart < opacEnd) { 
        for(i = opacStart; i <= opacEnd; i++) 
            { 
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            timer++; 
        } 
    } 
} 

//change the opacity for different browsers 
function changeOpac(opacity, id) { 
    var object = document.getElementById(id).style; 
    object.opacity = (opacity / 100); 
    object.MozOpacity = (opacity / 100); 
    object.KhtmlOpacity = (opacity / 100); 
    object.filter = "alpha(opacity=" + opacity + ")"; 
} 

function blendover(divid, imageid, imagefile, millisec) {
	fadefinished = false;
	var speed = Math.round(millisec / 100); 
	var timer = 0; 
	//set the current image as background 
	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")"; 
	    
	//make image transparent 
	changeOpac(0, imageid); 
     
	//make new image 
	document.getElementById(imageid).src = imagefile;

	//fade in image 
	for(i = 0; i <= 100; i++) { 
	        setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed)); 
	        timer++; 
	}
	setTimeout("fadeisfinished()",(timer * speed)); 
}

function fadeisfinished() {
	fadefinished = true;
}
 
function changeimage(divid) {
	if ((document.getElementById("img_blend").name != 'inf') && (divid == 1)){
    		document.getElementById("img_inf").src = src_btn + "main_inf_2.gif";
	    	document.getElementById("img_idm").src = src_btn + "main_idm_1.gif";
		document.getElementById("img_web").src = src_btn + "main_web_1.gif";
		document.getElementById("img_service").src = src_btn + "main_service_1.gif";
		document.getElementById("img_blend").name = "inf";
	    	blendover('div_blend','img_blend', 'fileadmin/img_backgrounds/main_inf.jpg',800);		
  	}
  	else if ((document.getElementById("img_blend").name != 'idm') && (divid == 2)) {
    		document.getElementById("img_inf").src = src_btn + "main_inf_1.gif";
	    	document.getElementById("img_idm").src = src_btn + "main_idm_2.gif";
		document.getElementById("img_web").src = src_btn + "main_web_1.gif";
		document.getElementById("img_service").src = src_btn + "main_service_1.gif";
		document.getElementById("img_blend").name = "idm";
	    	blendover('div_blend','img_blend', 'fileadmin/img_backgrounds/main_idm.jpg',800)
  	}
  	else if ((document.getElementById("img_blend").name != 'web') && (divid== 3)) {
    		document.getElementById("img_inf").src = src_btn + "main_inf_1.gif";
	    	document.getElementById("img_idm").src = src_btn + "main_idm_1.gif";
		document.getElementById("img_web").src = src_btn + "main_web_2.gif";
		document.getElementById("img_service").src = src_btn + "main_service_1.gif";
		document.getElementById("img_blend").name = "web";
    		blendover('div_blend','img_blend', 'fileadmin/img_backgrounds/main_web.gif',800);
  	}
  	else if ((document.getElementById("img_blend").name != 'service') && (divid == 4)) {
    		document.getElementById("img_inf").src = src_btn + "main_inf_1.gif";
    		document.getElementById("img_idm").src = src_btn + "main_idm_1.gif";
		document.getElementById("img_web").src = src_btn + "main_web_1.gif";
		document.getElementById("img_service").src = src_btn + "main_service_2.gif";
		document.getElementById("img_blend").name = "service";
    		blendover('div_blend','img_blend', 'fileadmin/img_backgrounds/main_service.jpg',800);

		//document.getElementById("more").href = "/ghPortal/portal/cn/gh/sus";
		//document.getElementById("morediv").style.marginLeft = "0";
		//document.getElementById("moreimg").src = "/ghPortal/resource/images/mehr.jpg";		
		//document.getElementById("snav4").style.display = "block";
	}
}