mult_table.js

    var rows = prompt("How many rows for your multiplication table?");
    var cols = prompt("How many columns for your multiplication table?");
    if(rows == "" || rows == null) rows = 10;
    if(cols== "" || cols== null) cols = 10;
    if(isNaN(cols) || isNan(rows)) 
          document.write("<h3>rows or columns are not numeric</h3>")
    createTable(rows, cols);
    function createTable(rows, cols)
    {
      var j=1;
      var output = "<table border='1' width='500' cellspacing='0'cellpadding='5'>";
      for(i=1;i<=rows;i++)
      {
    	output = output + "<tr>";
        while(j<=cols)
        {
  		  output = output + "<td>" + i*j + "</td>";
   		  j = j+1;
   		}
   		 output = output + "</tr>";
   		 j = 1;
    }
    output = output + "</table>";
    document.write(output);
    }