Question

I have two asp.net textboxes and need to put a validate function in javascript or jquery to validate either one or the other should accept a value. Both can not be left blank. And it should make visible the error label if both text boxes are empty.

Answer 1

The javascript validation method in your head tag:

function chkTxt(myForm)
{
  if(myForm.txt1.value == '' && myForm.txt2.value == '')
  {
    document.getElementById('msg').innerHTML = 'error';
    return false;
  }
  else
    return true;
}

You can set the onsubmit attribute of your form tag to call the method like this:

<form id="form1" runat="server" method="post" onsubmit="return chkTxt(this);">
    <div id="msg"></div>
    <asp:TextBox ID="txt1" runat="server"></asp:TextBox>
    <asp:TextBox ID="txt2" runat="server"></asp:TextBox>
    <button type="submit">submit</button>
</form>

Just a simple example.