Disable button before real email will be entered

Hello everybody,
I want button to be disabled before the real email will be entered.
What am I doing wrong?

<form action ="../includes/newsletter-signup.php" method="post" id="submit-email">
											
											<input  autocomplete="off" type="email" name="email-address" id ="email-address" placeholder="email">
											
											<input disabled="true" style="font-size: 16px;font-family: monospace;" class="btn-disabled btn-reset button button-blue" type="submit" id = "btn-reset"  value="sing up">
 
										</form>

and jquery

$(document).ready(function(){//check if email is real
  
// news subscription:
	$("#submit-email").validate({
		rules: {
			txtmail: {
				required: true,
				email: true
			}

		},
		messages: {
			email: "Please enter a valid email address"
		}

	}); // end reset-form
  
  $("#txtmail").on("blur", function(){
    if($("#submit-email").valid())
   {
       $("#btn-reset").removeAttr("disabled");
   }
 }); 
});