Figure 2


JavaScript method to verify numeric input.

function  isANumber(entry){
      if (!parseFloat(entry)) {
            alert("Please enter a numeric value.")
      }
      else {
            for (var i=0; i<entry.length; i++) {
                  if (entry.charAt(i) != " ") {
                      if (!parseFloat(entry.charAt(i))) {
                           alert("Please enter a numeric value.")
                            break
                      }
                  }
            }
      }
}