The DoCmd object exposes a long list of methods to use vba for access actions. OpenArgs is the last argument of the openform and openreport methods and basically allows you to pass an argument to the form or report.
To pass txtInvNo, or simply Text11, you would use:
Code:
DoCmd.OpenForm "frmCommLog",,,,,,me.Text11
then in your form open use something like
Code:
If not isnull(me.openargs) then
me.txtInvoiceNumber = Openargs
end if
The error message "item" is a property of the forms collection. More than likely you have something mis-spelled or missing.
You didn't answer the question whether you have option explicit declared which may point out your error.