Let's assume that your trigger checks the following code:
Condition field: obj1 && obj2 && obj3
In the same trigger you have selected "End1". What you can do, or seems to be the easiest solution is to set the "End1" back to "None". Next, write this in the On Activation Field: titleText ["Mission Complete","PLAIN"]; end=true;
Create a new trigger with the following parameters.
Condition: end
Type*: End1
* Don't know if that's the name for the dropdown list, I think it is.
Good luck.