function check_form_valid()
{
	if(document.F1.id_shahr.value == '')
	{
		alert('شهر انتخاب نشده است');
		return false;
	}
}

function bookmarksite(title,url){
if (window.sidebar) // firefox
	window.sidebar.addPanel(title, url, "");
else if(window.opera && window.print){ // opera
	var elem = document.createElement('a');
	elem.setAttribute('href',url);
	elem.setAttribute('title',title);
	elem.setAttribute('rel','sidebar');
	elem.click();
} 
else if(document.all)// ie
	window.external.AddFavorite(url, title);
}