function del_check()
{ 
	document.form1.type.value="delete";
	
	$flag=1;
	for(i=0;i<document.form1.elements.length;i++)
	{
		if ( document.form1.elements[i].type == "checkbox" && document.form1.elements[i].checked == true)
		{
			$flag=0;
		}
	}
	if($flag==0)
	{	
		return(confirm("Are you sure to delete the selected file(s)?"));
		document.form1.action="file_download.php";
		document.form1.submit();
		return true;
	}
	else
	{ 
		alert("Please select one or more file(s) to delete.");
		return false;
	}
}