function checknull1(){
		if(document.search1.select1.value==""){
			alert("Please select your search type! ");
			return false;
		}
		if(document.search1.hw_name.value==""||document.search1.hw_name.value=="please input keywords!"){
			alert("Please input your search keywords!");
			document.search1.hw_name.focus();
			return false;
		}
		return true;
	}