open window on click of button as modal dialog using javascript
===

i have to open window on click of button as modal dialog using javascript.
			 i have used window.open but it shows me two instances  parent page as well as pop up page.
			 when popup page is open then donot allow to click on parent page.   

 

    function openWindow()
        		{
        			var colno, pid;
        			var w = 950;
        			var h = 350;
        			var t = 0;
        			var l = 0;
        			var scrollbars = 1;
        			var modal = 'yes';
        
        			var reportWindow = "";
        			reportWindow = window.open("Search.aspx" + '', '', "width=" + w + ",height=" + h + ",left=" + l + ",top=" + t + ',scrollbars=' + scrollbars + 'modal' + modal);
        			reportWindow.focus();
        			return false;
        		}