Pop Up Window Code in ASP.NET Using JAVA Script

Below is the code to open pop up window is ASP.NET

in .aspx page

 <script type="text/javascript" >
function OpenWindow(url)
{
    newwindow = window.open(url, 'mynewwindow', 'width=500,height=400');  


}
</script>


in .aspx.cs page ( Server Side Code)


protected void OpenNewWindow(object sennder, EventArgs e)
    {
        StringBuilder popupScript = new StringBuilder();
        popupScript.Append("<script language='JavaScript'> window.open('UploadChecks.aspx?OrderSeqNo=" + lblOrderSeqno.Text + "', '', 'width=950, height=580,scrollbars,status,menubar=no,resizable,toolbar=no,titlebar=no,location=no');</script>");
       
    }

Java Script Code to compare two Date values in String

  function ValidateDate()
  {
 var fd=document.getElementById ('FromDate_txtDate');
 var td=document.getElementById ('ToDate_txtDate');

 if (Date.parse(fd.value) > Date.parse(td.value)) {

     alert("Invalid Date Range!\nFrom Date cannot be after To Date!")
    return false;
   }
  
}