function getHttp(){
	var xmlhttp=false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		xmlhttp = new XMLHttpRequest();
		if (xmlhttp.overrideMimeType) {
			xmlhttp.overrideMimeType('text/xml');
		}
	}
	if (window.ActiveXObject) { // IE
		try {
			xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}
	if (!xmlhttp) {
		alert('Giving up :( Cannot create an XMLHTTP instance');
		return false;
	}
	return xmlhttp;
}

function submitAjax(vUrl,vSend){
	var xmlhttp = getHttp();
	xmlhttp.open('POST', vUrl, true);
	xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");



	xmlhttp.onreadystatechange = function(){
		if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
			eval(function(js){try{eval(js);}catch(e){alert(js);}})(xmlhttp.responseText);
		}
	}
	xmlhttp.send(vSend );
}

function $n(n){
	return document.getElementsByName(n)[0];
}
function $( id){
	return document.getElementById( id);
}

function submitForm( ){
	var objForm = document.getElementById( 'f');
	var objText = document.getElementsByName('wd')[0];
	if( objText.value == objText.defaultValue || objText.value == ''){
		alert('请输入搜索关键字!');
		objText.focus();
		return false;
	}
	objForm.submit();	
}

function check(){
	var obj = $n('user');
	if( obj.value == ''){
		alert('请输入您的名字!');
		obj.focus();
		return false;
	}
	return true;
}