Mult.js

/* javaScript file that creates a dynamic mulitplication tbody from values inserted in my form in the file Mult.js
   created by Andrew DiBiasio on Oct 23, 2014 */

var i;  //loop indices
var j;
var k;

function validateForm(a)  /* Returns true if number is positive */ {
  if (isNaN(a) || a < 0 || a == "") {
    alert("Please insert a positive number");  // alert the user that a problem has occured
    return false;
  }
  return true;
}

$(document).ready(function () /* waits till document is ready */ {
  $("#multiplicationForm").submit(function () { // trap the submit event *before* the action is executed

    if (validateForm(this.multiplyStart.value) == false) {   // validateForm is called on all four values validate mulitplyStart                                            
      this.multiplyStart.style.background = "#FC1501";       // if validation fails, foucs is given to the part of the form where the error occured.
      this.multiplyStart.getfocus();
      return false;
    }

    if (validateForm(this.multiplyEnd.value) == false) { // validate mulitplyEnd
      this.multiplyEnd.style.background = "#FC1501";
      this.multiplyEnd.getfocus();
      return false;
    }

    if (validateForm(this.multiplicandStart.value) == false) {  // validate mulitplicandStart
      this.multiplicandStart.style.background = "#FC1501";
      this.multiplicandStart.getfocus();
      return false;
    }

    if (validateForm(this.multiplicandEnd.value) == false) {  // validate mulitplicandEnd
      this.multiplicandEnd.style.background = "#FC1501";
      this.multiplicandEnd.getfocus();
      return false;
    }

    $("#tbody").empty();

    $("#tbody").append("<tr>");      // Here, I start my first table row
    $("#tbody").append($("<td></td>").text(" "));

    for (i = this.multiplyStart.value; i <= this.multiplyEnd.value; i++) {   // This loop creates my and completes the data
      $("#tbody").append($("<td></td>").text(i));                                            // for the rest of the table's first row
    }
    $("#tbody").append("</tr>");  // first table row is finished

    //  All other table rows are pouplated with data with the following code______________________________________________________________________________

    for (k = this.multiplicandStart.value; k <= multiplicandEnd.value; k++) // This loop moves the the rest of my tbody rows, they all have the same format
    {
      $("#tbody").append($("<tr>"));
      $("#tbody").append($("<td></td>").text(k));      // Here, I start all other rows after the first

      for (j = this.multiplyStart.value; j <= this.multiplyEnd.value; j++) {   // This loop creates my and completes the data
        $("#tbody").append($("<td></td>").text(k * j));                             // for the rest of the table rows  
      }

      $("#tbody").append("</tr>");  // a table row is finished
    }
  });
});  // end ready