Hi. You could have it even more simple if you want: Simply have the field formatted as a checkbox set with a value list with custom value 1: see screenshots. Then your users simply click the checkbox to authorise it or unclick it to de-authorise it. Regarding committing the record - all the user needs to do is click outside the field and it will commit it.
Alternately, if you want it to be scripted it could be like this.
HTH - Chris
exactly what I was after, I hadn't figured out I could just type "1" into the calculation box to get it to just set 1!
Thanks for the assist, its now working as I need it,