Here how to open an Input Box and get the value inserted by the user
Local Integer OK Local Char VALEUR #SOH = Object Sale Order Call SAICAR(VALEUR,"Title of window","Field caption","SOH",0,0,"",OK) From GESECRAN Infbox VALEUR + " " + num$(OK)
Here the screenshot of the Input box as per the previous code example:

The value inserted is stored in the variable VALEUR and to know which button is clicked you can refer at the variable OK:
OK = 2 button OK is clicked
OK = 1 button Fine is clicked