//img preload
loader = new Image(16,16); 
loader.src = "./images/loader.gif";
//fade interval
var interval = 400;

function loadChart()
{	
		//fade out
		opacity("imgChart", 100, 0, interval);
		//get new chart src
		setTimeout("getChart()", interval);
}
function getChart()
{
	if(document.getElementById)
    {
        //display loading img
        //document.getElementById("imgChart").src = loader.src;
        //document.getElementById("imgChart").className = "loading";
        //get drop down values
        var chartType = document.getElementById("xchartlbl");
        var chartInterval = document.getElementById("xcharthist");
        //call web service
        var pl = new SOAPClientParameters();
        pl.add("rateType", chartType.value);
        pl.add("intervalId", chartInterval.value);
        pl.add("siteId", "MarkOne");
        SOAPClient.invoke("./Charts.asmx", "GetChartURL", pl, true, getChart_callBack);
    }
}
function getChart_callBack(retVal)
{
     //set src of new image
     //document.getElementById("imgChart").className = "";    
     document.getElementById("imgChart").src = retVal;     
     //fade in
     opacity("imgChart", 0, 100, interval);
}
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 + ")"; 
}