$(document).ready(function(){	
	$("#txt_username").blur(function()
	{
		var username_length;		
		username_length = $("#txt_username").val().length;			
		$("#username_warning").empty();
		
		if (username_length < 4)
			$("#username_warning").append("Username is too short");
	});
	
	$("#txt_password").blur(function()
	{
		var password_length;		
		password_length = $("#txt_password").val().length;			
		$("#password_warning").empty();
		
		if (password_length < 6)
			$("#password_warning").append("Password is too short");
	});
});