No Main or Selection Expression in Formula

I am trying to create an action button that will display a drop down list of choices.
When I enter a formula such as:
list:=@DbColumn(.....) or choice:=@PickList(....)
I get the Formula Error that "No Main or Selection Expression in Formula".  If I remove list:= or choice:=, I do not get any error message.
Why is this?
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After the field or variable assignment notes formula language expects a statement next to the assignment statement.

So enter "" after the assignment statement.

Good Luck

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You get this message because a formula must result to something.  If you put List := @DbColumn(....), then you must follow it with a semicolon and 'list' like this:

List := @DbColumn(.....);

List is a temporary variable used in formula language.

I would need more information to help you with what you are doing, for example, where is the action button located, what sort of information is in the drop down list, etc.

Chris_mAuthor Commented:
Thank you both, I have now worked out what I was doing wrong as a result of your input!
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