You cant use form boxes in a query if there's nothing in them..so..
Test all controls for a possible filter then build the sql.
on btnFind_Click()...
Code:
dim sSql as string, sWhere as string
if not isnull(cboState) then sWhere = sWhere & " and [state]='" & cboState & "'"
if not IsNull(txtName) then sWhere = sWhere & " and [Name]='" & txtName & "'"
if not IsNull(chkContact) then sWhere = sWhere & " and [Contact]=" & chkContact.value
'remove 1st And
sWhere= mid(sWhere,4)
sSql = "SELECT * FROM tblCompany WHERE " & sWhere
frmResults.Recordsource = sSql