在后面的代码上调用Javascript函数

Question

I am new to Asp.Net, I want my login page to be validate on Button Click using Java script but on .cs file. Here is my code:

<script type="text/javascript">
    function CheckisEmpty()
    {
        var username = document.getElementById('txtUserName').innerHTML;
        var password = document.getElementById('txtPwd').innerHTML;

        if (username != '' || password != '')
        {

            return true;
        }
        else
        {
            alert("Feild Cannot Be Left Blank");
            return false;
        }

    }
</script>

<asp:Button ID="btnLogin" Text="Login" runat="server" Width="120px" OnClick="btnLogin_Click" OnClientClick="return CheckisEmpty();" CssClass="button"></asp:Button>

btnLogin.Attributes.Add("OnClick", "CheckisEmpty()");

Where am I wrong?

Answer 1

on your aspx page add this attribute on your button onClientClick="CheckisEmpty()"

No need to do on .cs page.

This way, first the js function will be executed, If the validation is successful, return true from the js function , else return false and give some notification to the user. When false is returned, The process will not continue to your cs function and thus page will not be post-back.