title: Regular expression for decimal value upto some position
body: <p>In Input text box if somebody enter any value it should check the regular expression</p>
  
  <p>maybe the value will be decimal or non decimal</p>
  
  <p>before decimal it should have four digit </p>
  
  <p>after decimal it should have only these three value (.25 , .75 , .5)</p>
  
  <p>like:-</p>
  
  <p>1.5</p>
  
  <p>12.25</p>
  
  <p>123.75</p>
  
  <p>1234.75</p>
  
  <p>1234</p>
  
  <p>123</p>
  
  <p>12</p>
  
  <p>1</p>
  
  <p>Please help me out</p>