Add the General Check node () under a User Input node to force users to enter values that only match a certain pattern. An error message notifies the user that an illegal value was entered. The Settings window has the following section:

From the Type of check list, choose Match regular expression (the default) or Require parables expression.

Enter the pattern in the Regular expression text field. Regular expressions supports a wide variety of string matching functionality, and the table below only list a few examples:

When the match fails for an entered value, an error message displays. Enter the error message to display in the Error message text field.