function Check()
{
var UserName = document.getElementById("t1").value;
var UserPwd = document.getElementById("t2").value;
if(Trim(UserName)=="" || Trim(UserPwd)=="")
{
alert("不能为空");
}
}
function Trim(str)
{
for(var i=0 ; i<str.length ; i++)
{
str = str.replace(" ","")
}
return str;
}
{
var UserName = document.getElementById("t1").value;
var UserPwd = document.getElementById("t2").value;
if(Trim(UserName)=="" || Trim(UserPwd)=="")
{
alert("不能为空");
}
}
function Trim(str)
{
for(var i=0 ; i<str.length ; i++)
{
str = str.replace(" ","")
}
return str;
}
alert("t1不能为空")if(document.getElementById("t2").value.length<1)
alert("t2不能为空")
//如果str = " a";str.length在replace后会变的,只执行2次就不执行了
//str = str.replace(/\s/g,"")
for(var i=0 ; i<str.length ; i++)
{
str = str.replace(" ","")
}
<head runat="server">
<title>练习</title>
<script>
//在表单类就用表单名或者
function Check()
{
var ct=Form1.test.value;//或者document.getElementById("test").value;
if(ct == "")
{
alert("该值不能为空!");
return false;
}
alert(ct+":"+document.getElementById("t1").value);
}
</script>
</head>
<body>
<form id="Form1" name="Form1" runat ="server">
<asp:textbox id="test" runat ="server"></asp:textbox>
<asp:TextBox ID="t1" runat="server"></asp:TextBox>
<input id="Button1" type="button" value="提交" runat ="server" OnClick="javascript:Check();">
</form>
</body>
</html>