title: converting a string to a number
body: <p>I have a script that receives a string that contains a number.</p>
  
  <p>The string may be "1000" or "1000.25" or "1111111111111111111111111" or "abc111"</p>
  
  <p>I would like to be able to check firstly if it is a number, and fail if it is not, and also fail if there are fractions.</p>
  
  <p>I am having trouble converting to a suitable number type that still lets me check for the mentioned scenarios.</p>
  
  <p>Basically I need to check that the string only contains an integer number, no matter how large that number may be.</p>
  
  <p>Would really appreciate some help on this one.</p>
  
  <p>Thanks</p>
  
  <p>Dave</p>