function shieldDiv(conID){
	var conID = conID;
    var me = this;
    var shield;
    var c = 0;//渐变的透明度
    var ad;//渐变的临时变量
    me.init = function(){
        if(document.getElementById("shield")){
            shield = document.getElementById("shield");
            shield.style.display = "block";
            shield.style.filter = "alpha(opacity=0)";
            shield.style.opacity = 0;
        }else{
            shield = document.createElement("div");
            shield.id = "shield";
			shield.style.cssText = 'position:absolute;display:none;left:0px;top:0px;background:#666;text-align:center;opacity:0;filter:alpha(opacity=0);z-index:8;width:100%;height:' + ((document.documentElement.clientHeight>document.documentElement.scrollHeight)?document.documentElement.clientHeight:document.documentElement.scrollHeight) + 'px';
            document.body.appendChild(shield);
        }    
    }
    me.setOpacity = function(obj,opacity){
	    if(document.all)
	        obj.style.filter="alpha(opacity=\"" + opacity + "\")";
	    else
	        obj.style.opacity=opacity/100;
    }
    me.doAlpha = function(){
        c+=5;
	    if(c>50){clearInterval(ad);return 0;}
	    me.setOpacity(shield,c);
    }
    me.show = function(){
        me.init();
        document.getElementById("shield").style.display = "block";
		document.getElementById(conID).style.display = "block";
		document.getElementById("shield").onclick = function(event){
			var evt = event?event:window.event;
			if(document.all){
				evt.cancelBubble = true;
				if(evt.srcElement.id == "shield"){
					document.getElementById(conID).style.display = "none";
					document.getElementById("shield").style.display = "none";
				}
			}else{
				evt.stopPropagation();
				if(evt.target.id == "shield"){
					document.getElementById(conID).style.display = "none";
					document.getElementById("shield").style.display = "none";
				}
			}
		}
        ad = setInterval(me.doAlpha,1);
    }
    me.hide = function(){
		document.getElementById(conID).style.display = "none";
        if(document.getElementById("shield"))
            document.getElementById("shield").style.display = "none";
    }
	
}