Javascript to sum fields in gridview not working

Posted on 2008-10-29
Last Modified: 2012-05-05
I have some javascript functions that run on the onkeyup event of some textboxs in a gridview.   Now I'm trying to add an additional function to sum some more.  I'm getting an error on page at the bottom of the browser when the event fires.  The error lists at the line before my new function and says "Object does not support this property or method".

My code is shown below.  The new function I'm adding in SumItUpB.  The other functions still work good (Thanks to some previous help from Experts-Exchange).
The javascript code


 function SumItUp(textResult)


				var x = 0;

				var y = 0;

				var z = 0;


				var myArray = new Array();

				//add array items, this calls the public server variable we build in rowdatabound

				<%= JSArray %>

				//sum it:

				for (x = 0; x < myArray.length; x++)


				    //multiply the value times one to trick js into always thinking the variable is a number

				    y = y + (myArray[x] * 1.00);


				//display the result

				z = (y * 1);

			    document.getElementById(textResult).value = z.toFixed(2);

				//document.getElementById(textResult).value = (y * 1.00);




			function SumItUpB(textResult)


	         var x = 0;

			 var y = 0;


			  var myArray2 = new Array();

			  <%= JSArray2 %>

			  for (x = 0; x < myArray2.length; x++);


			        y = y + (myArray2[x] * 1.00);



			  document.getElementById(textResult).value = (y * 1);




			function Multiply(text1, text2, textResult)


				var x = document.getElementById(text1).value;

				var y = document.getElementById(text2).value;

				if(IsNumeric(x) == true && IsNumeric(y) == true)


				document.getElementById(textResult).value = (x * 1) * (y * 1.00);




				document.getElementById(textResult).value = '';





			function IsNumeric(sText)


               var ValidChars = "0123456789.-";

               var IsNumber=true;

               var Char;

               for (i = 0; i < sText.length && IsNumber == true; i++) 


                  Char = sText.charAt(i); 

                  if (ValidChars.indexOf(Char) == -1) 


                     IsNumber = false;



               return IsNumber;


The C# Code:


 protected void gvMealsForSell_RowDataBound(object sender, GridViewRowEventArgs e)



        if (e.Row.RowType == DataControlRowType.DataRow)


            // Get values for calculation

            TextBox txtQuantity = (TextBox)e.Row.FindControl("txtNumberToBuy"); // quantity

            HiddenField hfMealPrice = (HiddenField)e.Row.FindControl("hfMealPrice"); // meal price

            HiddenField hfTotal = (HiddenField)e.Row.FindControl("hfTotal"); //total 


            txtQuantity.Text = "0"; // Default value


            // Add javascript to text box with calcualtion values

            txtQuantity.Attributes.Add("onkeyup", "javascript:Multiply('" + txtQuantity.ClientID + "','" + hfMealPrice.ClientID + "','" + hfTotal.ClientID + "');SumItUp('" + this.txtTotalDue.ClientID + "');SumItUpB('" + this.txtTotalItems.ClientID + "')");


            //Set up javascript array

            JSArray  += "myArray[" + counter.ToString() + "] = document.getElementById('" + hfTotal.ClientID + "').value;" + Environment.NewLine;

            JSArray2 += "myArray2[" + counter.ToString() + "] = document.getElemenetById('" + txtQuantity.ClientID + "').text;" + Environment.NewLine;


            //counter to maintain the js array index

            counter += 1; 



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Question by:weimha
LVL 28

Assisted Solution

by:Pravin Asar
Pravin Asar earned 500 total points
ID: 22845279
To do math operations on the variable values, it is a good idea to parse as Float


var x= 1.0;
var y = "2.5";

var sum = parseFloat(x) + parseFloat(y);
alert (sum);

So where you are trying to add/multiply the variable, please use parseFloat


Accepted Solution

weimha earned 0 total points
ID: 23008723
I've decided not to do this.
Thanks for the input.

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