function viewLink(dropdownlistId)
{   
    var dropdown = document.getElementById(dropdownlistId);
    var index = dropdown.selectedIndex;
    var option = dropdown.options[index];
    var url = option.value;
    window.open(url,'','scrollbars=yes,status=yes,resizable=yes,menubar=yes,toolbar=yes,titlebar=yes');
    return false;
}