function CenterMessage(targetmessage, targetwidth, targetheight)
{
 document.getElementById(targetmessage).style.display = "none";
 document.getElementById('backdrop').style.display = "none";

 document.getElementById(targetmessage).style.left = document.body.clientWidth/2-(targetwidth/2) + "px";
 if (document.body.clientWidth/2-(targetwidth/2) <= 0)
  document.getElementById(targetmessage).style.left = "2px";

  document.getElementById(targetmessage).style.top = "100px";

 var browserwidth;
 var browserheight;
 var offsetx;
 var offsety;
if (typeof(window.innerHeight) == "number")
{
 browserwidth = window.innerWidth;
 browserheight = window.innerHeight; 
 offsetx = window.scrollMaxX;
 offsetx = window.pageXOffset;//safari && FF
 offsety = window.pageYOffset;//safari && FF

}
else if (document.documentElement && (document.documentElement.clientHeight || document.documentElement.clientWidth))
{
//Internet Explorer 6 and later
 browserwidth = document.documentElement.clientWidth;
 browserheight = document.documentElement.clientHeight;
 offsetx = document.documentElement.scrollLeft;
 offsety = document.documentElement.scrollTop;

}
else if (document.body && (document.body.clientHeight || document.body.clientWidth))
{
//Internet Explorer 4
 browserwidth = document.body.clientWidth;
 browserheight = document.body.clientHeight;
 offsetx = document.documentElement.scrollLeft;
 offsety = document.documentElement.scrollTop;
}
 var topoffset;
 topoffset = document.documentElement.scrollTop;
 if (document.body.scrollTop)
  topoffset = document.body.scrollTop;

 var topposition = (Math.ceil((browserheight)/2) + offsety) - 200;

 if (topposition < 100)
  topposition = 100;

 document.getElementById(targetmessage).style.top = topposition + "px";
 document.getElementById(targetmessage).style.width = targetwidth+"px";
 document.getElementById(targetmessage).style.display = "block";
}

function ClearMessage(targetmessage)
{
 document.getElementById(targetmessage).style.display = "none";
 document.getElementById('backdrop').style.display = "none";
 document.getElementById(targetmessage).innerHTML = "";
}

function CloseMessage(targetmessage)
{
 document.getElementById(targetmessage).style.display = "none";
 document.getElementById('backdrop').style.display = "none";
}

function ShowMessage(targetmessage)
{
 document.getElementById(targetmessage).style.display = "block";
 document.getElementById('backdrop').style.display = "block";
}