You don't want to pass the form name (as that would just be a string containing the name), you want to pass the form (which allows you to use the properties etc).

You would add/use the parameter like this:
Code:
Sub recordposition(theForm as Form)
    
    Select Case theForm.Recordset.AbsolutePosition
    Case 0    
        theForm.cmdnext.Visible = True
        theForm.cmdprevious.Visible = False
...
..and pass the parameter like this:
Code:
recordposition Me
'or:
Call recordposition (Me)