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; 



Open in new window

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.

Featured Post

Why You Should Analyze Threat Actor TTPs

After years of analyzing threat actor behavior, it’s become clear that at any given time there are specific tactics, techniques, and procedures (TTPs) that are particularly prevalent. By analyzing and understanding these TTPs, you can dramatically enhance your security program.

Join & Write a Comment

Suggested Solutions

Introduction HTML checkboxes provide the perfect way for a web developer to receive client input when the client's options might be none, one or many.  But the PHP code for processing the checkboxes can be confusing at first.  What if a checkbox is…
Article by: DanRollins
This article describes a JavaScript program that creates a maze made of hexagonal cells.  In Part 2 (, we'll extend the program by adding a depth-…
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

706 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

20 Experts available now in Live!

Get 1:1 Help Now