How to check if input is a number and call a function accordingly?

Question

I have my code below..I need to modify it so that the input is checked if it is number.If its not a number, then a message has to be displayed as follows \" please enter only no

Answer 1

You may try like this:

if (!isNaN(parseFloat(obj)) && isFinite(obj);) 
  {
    compare();
  }
 else
  {

    alert("Please enter only numbers");
    return false;
  }