function OpenPopUp(MyFile,MyWindow,MyWidth,MyHeight)
{	  
var ns4 = (document.layers)? true:false; 	  //NS 4
var ie4 = (document.all)? true:false;	  //IE 4
var dom = (document.getElementById)? true:false;	  //DOM
var xMax, yMax, xOffset, yOffset;;	  
    if (ie4 || dom)
        {
        xMax = screen.width;
        yMax = screen.height;
        }
    else if (ns4)
        {
        xMax = window.outerWidth;
        yMax = window.outerHeight;
        }
    else
        {
        xMax = 800;
        yMax = 600;
        }
    xOffset = (xMax - MyWidth)/2;
    yOffset = (yMax - MyHeight)/2;
    window.open(MyFile,MyWindow,'width='+MyWidth
+',height='+MyHeight
+',screenX='+xOffset
+',screenY='+yOffset
+',top='+yOffset
+',left='+xOffset
+',status=no,location=yes,toolbar=no,directories=no,resizable=no,scrollbars=no,status=yes,location=no');
    }