Question

It has to be a minor issue but I just can’t find it. Maybe one of you can help me here.

Javascript

  function white_space(field)
  {
     field.value = field.value.replace(/^\s+/, "");
  }
  function validate(){
    var formname=document.reg_form;
    var fname=formname.fname.value;
    var mess="";

  var uname=formname.prodName.value;
    if(uname==""){
    mess= mess+"User Name cannot be blank\n";

    }
   var pass=formname.prodPrice.value;
    if(pass==""){
     mess= mess+"Password cannot be blank\n";   
}

if(mess){
  alert(mess);
  return false;

   }
 }

HTML FORM

 <form class="form-signin" action="#" onSubmit="return validate();" name="reg_form">
    <h2 class="form-signin-heading">Sign-In</h2>
    <input type="text" class="input-block-level" name="prodName" placeholder="Email address" onKeyPress="white_space(this)">
    <input type="password" class="input-block-level" name="prodPrice" placeholder="Password" onKeyPress="white_space(this)">
    <label class="checkbox">
      <input type="checkbox" value="remember-me"> Remember me
    </label>


    <button class="btn btn-large btn-primary" type="submit">Sign in</button>
  </form>

Error

Browser doesn’t show an empty string error.

Answer 1

in your case this line

var fname=formname.fname.value;

throw error while execution validate function, as there is no element with fname into the form, comment it and you are fine
http://jsbin.com/oxawil/1