passing text box input to DLookUp

[MachineBoy]

How would I pass input from the user entered into a text box as part of a parameter query in a DLookup statement
ex -

code
If IsNull(DLookup("[Project]", "Query5Act", "[Project] = 'strText'&quot) Then
/ code

where Project is a field in a table and strText would be the particular Project that the user entered into a text box as part of the parameter query ("Query5Act&quot?

 

[930driver]

If IsNull(DLookup("[Project]", "Query5Act", "[Project] = " & txtInput)) Then

txtInput is the name of the Project input box on your form "The Key, The Whole Key, and Nothing But The Key, So Help Me Codd!"