{{omit from|ACL2}}
{{omit from|Applesoft BASIC|no concept of a GUI}}
{{omit from|AWK|no concept of a GUI}}
{{omit from|Batch File}}
{{omit from|Blast}}
{{omit from|Brainf***}}
{{omit from|Commodore BASIC}}
{{omit from|GUISS|Only makes use of installed applications}}
{{omit from|Integer BASIC|no concept of a GUI}}
{{omit from|Lilypond}}
{{omit from|Logtalk}}
{{omit from|Lotus 123}}
{{omit from|Maxima}}
{{omit from|PARI/GP}}
{{omit from|PostScript}}
{{omit from|Retro}}
{{omit from|SQL PL|It does not handle GUI}}


Almost every application needs to communicate with the user in some way.
Therefore, a substantial part of the code deals with the interaction
of program logic with GUI components.

Typically, the following is needed:

* put values into input fields under program control
* read and check input from the user
* pop up dialogs to query the user for further information


;Task:
For a minimal "application", write a program that presents a form with three components to the user:
::* a numeric input field ("Value")
::* a button ("increment")
::* a button ("random")


The field is initialized to zero.

The user may manually enter a new value into the field,
or increment its value with the "increment" button.

Entering a non-numeric value should be either impossible,
or issue an error message.

Pressing the "random" button presents a confirmation dialog,
and resets the field's value to a random value if the answer is "Yes".

(This task may be regarded as an extension of the task [[Simple windowed application]]).<br><br>