function addOption(selectbox,text,value )
	{
		var optn = document.createElement("OPTION");
		optn.text = text;
		optn.value = value;
		selectbox.options.add(optn);
	}


	function checkEnter(e){ 
		var characterCode 

		if(e && e.which){ 
			e = e
			characterCode = e.which 
		} else{
			e = event
			characterCode = e.keyCode 
		}

		if(characterCode == 13){ 
			return true
		} else{
			return false
		}
	}

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