imagen html como botón Enviar

<form id='formName' name='formName' onsubmit='redirect();return false;'>
  <div class="style7">
    <input type='text' id='userInput' name='userInput' value=''>
    <input type="image" name="submit" src="https://jekyllcodex.org/uploads/grumpycat.jpg" border="0" alt="Submit" style="width: 50px;" />
  </div>
</form>
lukas degle