JavaScript Function num_phone()

Function num_phone()

This Function  is used to veryfy whether user enter the number or not using keypress event.

For exaample 
 < input type=text name=txt_phno onkeypres="num_phone();" >  


function num_phone()
{   
 // nummeric  with hybhen and blankspace

  if (event.keyCode>47 && event.keyCode <58)
  {
   return true;
  }
  
  if (event.keyCode==32)//blankspace
  {
   return true;
  }
  
  if (event.keyCode==45)
  {
   return true;
  }
  if (event.keyCode==45) // - HYPHEN
  {
   return true;
  }
  
  event.keyCode=0;
  return false;

}