function display_verify(insertText, elementId)
{
    if (insertText != '' && insertText != null)
    { 
        document.getElementById(elementId).style.display = 'block';
    }
    else
    {
        document.getElementById(elementId).style.display = 'none';
    }
};

function alphanumeric(insertText)
{
	for(var j=0; j<insertText.length; j++)
	{
        var letter = insertText.charAt(j);
        var letterCode = letter.charCodeAt(0);
		  
		if((letterCode > 47 && letterCode<58) || (letterCode > 64 && letterCode<91) || (letterCode > 96 && letterCode < 123))
		{
		}
		else	
		{
		    return false;
		}
    }
    return true;
}


function check_availability(type)
{
  var e = document.getElementById('username');
  
  if (alphanumeric(e.value) == false)
  {
      alert('Username must contain only letters and numbers');
      return false;
  }
  
  xajax_xajax_username_availability(e.value, type);
};