验证用户名 密码---前端

 

表单验证

<script>

function showTips(id,info){
document.getElementById(id+"span").innerHTML="<font color=\'red\'>"+info+"</font>"

}
//onblur="check(\'user\',\'用户名不能为空\')"
function check(id,info){
var el = document.getElementById(id).value;
//校验
if(el==""){
document.getElementById(id+"span").innerHTML="<font color=\'red\'>"+info+"</font>"
}else{
document.getElementById(id+"span").innerHTML="";
}
}
</script>