function ZOOM_TO_SCREEN(obj)
{
    var element = document.getElementById(obj);
    var width =parseInt(screen.width);
    var height = parseInt(document.body.offsetHeight);
    var _width = parseInt(element.offsetWidth);  
    var _height = parseInt(element.offsetHeight);
    element.style.top = (height-_height)/2+"px";
    element.style.left = (width-_width)/2+"px";
}


var total_pages=0;
var current_index=0;
function pre()
{
    if(current_index>0)
    {
        current_index--;
        change();
    }
   
}
function next()
{
    if(current_index<total_pages-1)
    {
        current_index++;
        change();
    }
}
function show()
{
    current_index = parseInt(document.getElementById("main_img").name.split("_")[1]);
   
//    var scroll_top=0;
////    if(document.documentElement&&document.documentElement.scrollTop)
////    {
////        scroll_top=document.documentElement.scrollTop;
////    }
////    else if(document.body)
////    {
////        scroll_top=document.body.scrollTop;
////    };
//    var element = document.getElementById("loading");
//    element.style.top = scroll_top+"px";
    
    var temp = document.getElementsByName("url");
    document.getElementById("current_img").src=temp[current_index].value;
    document.getElementById("loading").style.display="block";
     if(current_index==0)
    {
        document.getElementById("img_pre").style.display="none";
    }
    else
    {
        document.getElementById("img_pre").style.display="block";
    }
    if(current_index==total_pages-1)
    {
        document.getElementById("img_next").style.display="none";
    }
    else
    {
        document.getElementById("img_next").style.display="block";
    }
     ZOOM_TO_SCREEN("loading");
    self.location="#loading";
}
function change()
{
    var temp = document.getElementsByName("url");
    document.getElementById("current_img").src=temp[current_index].value;
    document.getElementById("loading").style.display="block";
     if(current_index==0)
    {
        document.getElementById("img_pre").style.display="none";
    }
    else
    {
        document.getElementById("img_pre").style.display="block";
    }
    if(current_index==total_pages-1)
    {
        document.getElementById("img_next").style.display="none";
    }
    else
    {
        document.getElementById("img_next").style.display="block";
    }
    ZOOM_TO_SCREEN("loading");
    self.location="#loading";

}