You have no command to print a report. You need to include the Docmd line in your code or else access doesn't know what to do. You have not defined your report either.
Code:
Private Sub Command28_Click()
On Error GoTo Err_Command28_Click
Dim stDocName As String
stDocName = "Submission"
DoCmd.OpenReport stDocName, acViewPreview, , "[ID]=Forms!frmClients!ID"
Exit_Command28_Click:
Exit Sub
Err_Command28_Click:
MsgBox Err.Description
Resume Exit_Command28_Click
End Sub
You will also need to make sure that you have a field that identifies the record. In my case it is the field [ID]. My report name is Submission. You will need to change it to yours. This code will print as a report only the record that is open in your form.