title: Check if the entered text uses only English letters
body: <p>I am working on an iPhone application and need to make sure the entered text is composed of only a to z and numbers. </p>
  
  <p>I don't want the user to use other languages letters like those with accents or dots above them.</p>
  
  <p>EDIT: I am new to this RegEx, so if you please give me a code or a link, i will be really thankful.</p>