>Hi, everyone!...
>
>How do I detect if the content of a textbox has changed?...
>
>Thanks in advance!
>Carlos Burgos

Save value in GotFocus and check in Valid event, if the value is the same.

You can use tag property to save value (you would need to transform to text) or add a new property, e.g.

GotFocus

this.AddProperty('CurrentValue', this.value)
this.CurrentValue = this.value

Valid event

if this.value <> this.CurrentValue 
  * Perform validation
endif