Javascript - validation, numbers only

Question

I\'m trying to get my login form to only validate if only numbers were inputted. I can it to work if the input is only digits, but when i type any characters after a number,

Answer 1

Late answer,but may be this will help someone

function isNumber(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

Use will be like

nn=document.forms["myForm"]["num"].value;

ans=isNumber(nn);

if(ans)
{
    //only numbers
}

This ans was found from here with huge vote

Validate numbers in JavaScript - IsNumeric()