Save Application from Script

Is it possible to save and overwrite the existing application from a script?

I have a ValueBox tracking the running hours of a piece of equipment (duration in non-zero state from an aggregate start time). I have a script that replaced the aggregate start time of the value box with a value entered into a TextBox by a user (on text change script event). 

Is there a line of code that will prompt the user to save the application with the new date that they input for the TextBox?

Script:

public void TextBox2_OnTextChange(object sender, string text)

{
    ValueBox2.AggregateStartTime = TextBox2.Text;
    // code here to save the application with current text box and aggregate start time values
}