Using AJAX to update an input textbox from an input textbox

[Kurtis]

The problem is as followed:

I have 3 text boxes: Fee, Donation, Total.

Fee cannot be modified, and the user cannot type in this textbox

Donation starts at 0 and the user can change the value based on what they want to donate

Total needs to be updated based on what the user types in donation. It needs to be Donation+Fee

How can I use AJAX to make the Total textbox get updated on the fly based on what is entered in Donation?

 

 

 

[Viktor Tachev]

Hello Kurtis,

In order to calculate the value for the Total TextBox you would need to use JavaScript to get the values from the other two textboxes and calculate the result. Please examine the thread below that elaborates on the functionality.

• http://stackoverflow.com/questions/477543/how-do-i-assign-value-to-a-textbox-using-javascript

Since you would like to use the values of the TextBoxes server-side you can use a Button control that would initiate a postback. Then you can access the textboxes and their values on the server and implement the necessary custom logic.

In order to Ajax-enable the controls you can wrap the TextBoxes and the Button in a RadAjaxPanel.

• http://docs.telerik.com/devtools/aspnet-ajax/controls/ajaxpanel/overview

Regards,
Viktor Tachev
Telerik by Progress