output field ( total )


I need help please ..

I have 2 numeric input fields in the page; 

when the user fills the field , the third field will be the output (total of 2 input fields ) , the output will appears already when the 2 inputs fill .

How can i make the output field ? 

Hello Sara Ahmad,

Try to populate the variable with the addition of 2 fields on the OnChange Event Handler Action of the text box.

Screenshot 2023-11-04 030306.png
Screenshot 2023-11-04 030322.png

Hello @SARA

  • Just Drag and Drop 3 input Fields to your Main flow inside a Container, 
  • Bind Each Input Field With Local Variable, create 3 local variable of  type integer.
  • Now Create a On Change input action on first and second field in which user will enter number.

And write the logic to add two numbers

I have shared a demo and a sample that would help you,


But I suggest you to go through Outsystems Training Guided path to have a good understanding.


Tousif Khan


Hi Sara,

you can do few things

1- you can apply check on parameters change, if both fields are filled then only operation should be done.

2. or you can add a button name ex- add, after clicking this button only calculation will be done.



Hey @Sara Ahmad 

Step 1) In the screen create 3 local variables(Inp 1, Inp 2 and Output) and 2 input fields, and one button.

Step 2) On click of the client action after the start node 

Create a if condition and add condition (if inp 1 == nulldata() or inp 2 == nulldata()) if this condition is true, end the flow and inside the false branch drag an "assign" inside it +Output = Inp 1+ Inp 2).

Step 3) On the screen, store the value of input field in Inp 1 and second input field to Inp 2.

Step 4) On the screen drag the expression and give it the value to show the "Output" this is the variable we created initally. 

Please let us know if you need any help.

Shlok Agrawal

Hi Sara,

Please see the attachment file this will help you

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