a = Me.cboSearch.Value
sSQL = "select * from [tblLessee] where [a] = '" & Me.txtSearch & "' "
ors.Open sSQL, oConn, adOpenStatic, adLockReadOnly
Sorry OM I'm struggling with what your actual problem is here
a = Me.cboSearch.Value
This seem to be saying [a] is a module variable set by the comboBox ( By the way .Value is the dafault property so you don't need to type it at all. )
Yet the SQL string seems to be using [a] as the name of the field in the table. ( The [something] that follows WHERE should be the name of the field in the tblLessee that you're looking to match against the criteria in the txtString control. )
So:-
sSQL = "SELECT * FROM tblLessee WHERE [a] = '" & txtSearch & "';"
should work fine if txtString is the NAME of the control on the form.
Note this will find EXACT matches only.
G LS