title: PHP Regular Expression for currency
body: <p>I am curious about finding a regular expression for dollars.  My inputs and rules are that there can only be digits 0 to 9 and an optional deciaml point. If the decimal exists, it must have two 0 t 9 digits after it.</p>
  
  <p>So it can except:
  1000
  1000.99</p>
  
  <p>But not:
  10001.1
  1000.
  1,000
  $100.9</p>