//http://www.brainerror.net/scripts_js_blendtrans.php

/***** BEGIN BROWSER TEST *****/
function switchBlend(){
	if (OS == "WIN"){
		if(BrowserType=="IE" && BrowserVersion < 7){
			//if(BrowserVersion < 6){
				return false;
			//}else{
			//	var av = navigator.appVersion;
			//	var msie = av.indexOf("MSIE");
			//	if(parseInt(av.substr(msie+7, 2)) == 0 && parseInt(av.substr(msie+10, 2)) > 27){
			//		return false;
			//	}else return true;
			//} 
		}else return true;
	}else return true;
}
/***** END BROWSER TEST *****/

/***** FORCE DROPDOWN MENU TO TOP *****/
function containertotop(header, zindex) {
    var x = document.getElementById(header);
	x.style.position = "relative";
    x.style.zIndex = zindex;
}
/***** END FORCE ******/

/***** EVALUATE TRUE POST IE7 SP1 *****/

function blendimageBT(divid, imageid, imagefile, urlid, urlfile, millisec) {
	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
        changeOpacBT(0, imageid);
      
        //make new image
	    //set to display none to reduce flickering
	    //document.getElementById(imageid).src = imagefile;
	    document.getElementById(imageid).style.display = "none";
	    document.getElementById(imageid).style.visibilty = "hidden";
	    setTimeout("document.getElementById('" + imageid + "').src = '" + imagefile + "';", 100);

  	    //fade in image
        if (OS == "WIN"){
		    for(i = 0; i <= 100; i++) {
			    //show again after updating opacity to reduce flickering
			    if(i==1){
				    document.getElementById(imageid).style.display = "inline";
				    document.getElementById(imageid).style.visibilty = "visible";
			    }
			    document.getElementById(divid).style.filter = "alpha(opacity=" + 100-i + ";)";
			    setTimeout("changeOpacBT(" + i + ",'" + imageid + "')",(timer * speed));
			        if (i==75){
			             document.getElementById(urlid).href = urlfile;
			        }
			    timer++;
			    }
		    }
        else{
			    for(i = 0; i <= 100; i++) {
     		    //show again after updating opacity to reduce flickering
			    if(i==1){
			    document.getElementById(imageid).style.display = "inline";
			    document.getElementById(imageid).style.visibilty = "visible";
			    }
			    setTimeout("changeOpacBT(" + i + ",'" + imageid + "')",(timer * speed));
			        if (i==50){
			                 document.getElementById(urlid).href = urlfile;
			            }
			    timer++;
			    }
		    }
}

/***** CHANGE OPACITY FOR DIFFERENT BROWSERS *****/

function changeOpacBT(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  + ")";
}

/***** END EVALUATE TRUE *****/



/***** EVALUATE FALSE - PRE IE 7 SP1 *****/

function changeimageBT(imageid, imagefile, urlid, urlfile) {
        //For pre IE sp1
	    document.getElementById(imageid).src = imagefile;
	    document.getElementById(urlid).href = urlfile;    
}

/***** END EVALUATE FALSE *****/


// ? UNUSED FUNCTIONS ? //
 function shiftOpacityBT(id, millisec) {

	//if an element is invisible, make it visible, else make it invisible
	if(document.getElementById(id).style.opacity == 0) {
		opacityBT(id, 0, 100, millisec);
	} else {
		opacityBT(id, 100, 0, millisec);
	}
}

function opacityBT(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("changeOpacBT(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	} else if(opacStart < opacEnd) {
		for(i = opacStart; i <= opacEnd; i++)
			{
			setTimeout("changeOpacBT(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	}
}

function currentOpacBT(id, opacEnd, millisec) {
	//standard opacity is 100
	var currentOpac = 100;
	
	//if the element has an opacity set, get it
	if(document.getElementById(id).style.opacity < 100) {
		currentOpac = document.getElementById(id).style.opacity * 100;
	}
	//call for the function that changes the opacity
	opacityBT(id, currentOpac, opacEnd, millisec)
}