Thank you for your post.
You will be unable to do this in FileMaker Go. You will have to make changes to the database file in FileMaker Pro prior to moving it to Go.
You can create a conditional calculation that displays the button in Gray when the Auto-serial number doesn't exist, and black when it does exist. On top of that, set a script to the button that checks to see if the Auto-serial number exists. If not, then exit the script. Otherwise, it will take you to the new form. Once this is working, then you can copy it to FileMaker Go, or have FileMaker Go access the file remotely.
Let me know if you need additional clarification.
Sorry I must have entered the wrong forum, I have Filemaker Pro 11. I was having a problem setting up a script to change the button colors after searching the table to see if the index was committed or not.
How would I search the db for the index number and change the colors and option to enable the button?
Let's say your serial ID field is named __pk_REQID and this is a field of type Number.
a Conditional format expression: Not YourTable::__pk_REQID can be used to change the text and/or fill color of your button to show it as disabled.
The script performed by this button can be enclosed in an If block that checks this same field for a value:
If [Not YourTable::__pk_REQID]
#your script here
The button is not really disabled, it'll change color when you click it, but nothing will happen when you do unless the serial number field has a value.