PLEASE can someone tell me why Sorting (by the field button) is only prioritising one field.

I've created the scripts for 3 fields. I've gone over them a million times and redone them and still only 'Field2' will sort AND only descending. Once sorted that way, none of them will budge even though there seems to be no error with clicking on the button's on the other fields. If I sort using Sort Menu (which also insists on coming up with the 'Field2', I have to clear it each time) ,but then when I click the buttons to sort any of fileds again, they will only sort defaulting 'Field2' and descending. I hope this makes sense coz it's driving me nuts.

Do a manual sort using the criteria you want. Then edit the script that the button you are clicking is activating. Click OK and a dialog opens asking if you want to Keep or Replace the sort. Click the button that says Replace and finish the edit. Your script (and button) will now use the sort order you specified.

Pretty basic. You might want to refer to the manual or the online help and review how editing scripts works.