// 功能：打开遮挡层同时把下拉筐隐藏
var divId = "Div_Mask"
function openDivMask()
{	
 var divMask = document.getElementById(divId);
 if(!divMask){
 divMask = document.createElement("div");
 divMask.id = divId;	
 divMask.style.display = "block";
 divMask.style.top = divMask.style.left = divMask.style.margin = divMask.style.padding = "0px";
 var screenWidth;
	 var screenHeight;
	 if(document.body.scrollHeight<document.documentElement.offsetHeight){
		 screenHeight = document.documentElement.offsetHeight + "px";
	 }
	 else{
		 screenHeight = document.body.scrollHeight + "px";
	 }
	 if(document.body.scrollWidth<document.documentElement.offsetWidthh){
		 screenWidth = document.documentElement.offsetWidth + "px";
	 }
	 else{
		 screenWidth = document.body.scrollWidth + "px";
	 }	
	 divMask.style.width = screenWidth;
	 divMask.style.height = screenHeight;
	 divMask.style.position = "absolute";
	 divMask.style.zIndex = "99";
	 divMask.style.background = "#D3D3D3";
	 divMask.style.filter = "alpha(opacity=50)";
	 divMask.style.opacity = 50/100;
	 divMask.style.MozOpacity = 50/100;	
	 document.body.appendChild(divMask);	
	}else{
	 divMask.style.display = "block";
	}	
	//屏蔽SELECT
	var allselect = document.getElementsByTagName("select");
	if (allselect != null && allselect.length > 0){
	 for (var i=0; i<allselect.length; i++){ 
		 allselect[i].style.visibility = "hidden";
 }
 }
}
// 功能：关闭遮挡层同时把下拉筐显示
function closeDivMask()
{
	var objDialog = document.getElementById(divId);
	if (objDialog) objDialog.style.display = "none";
	
	var allselect = document.getElementsByTagName("select");
	if (allselect != null && allselect.length > 0){
	 for (var i=0; i<allselect.length; i++){
		 allselect[i].style.visibility = "visible";
 }
 }	 	 
}