About Text Box
The PTC Mathcad Prime scriptable control Text Box enables you to accept a user input in the form of text, which can be used as a string or number data for calculations. You can modify the behavior of the control on input and the resulting output through a script in the Exec event using the Text Box class. You can change the appearance of a Text Box by right-clicking and choosing >
There are three events in the default script for Text Box: Start, Exec, and Stop. Because this text box control takes what is entered and returns it as an output, there is no code in either the Start or Stop events. All actions associated with processing user entries in the text box should be written in the Exec event, including parsing text, converting the data type, or any other processes. Some formatting can be scripted in the Start event or using the Properties tab.