Dan:

Thanks again for your input.

Creating appended queries with WHERE 1 = @p1 is a technique I learned
from VB programmers in the MSDN Forum.  It has always worked for me so
I have used it for complex searches like this.  I have always assumed
that 1 = @p1 is a placeholder that simply opens the query to
additional parameters with values that can be defined at runtime.

As I reflect on your comments above (and the apparent limitations of
this approach), I am inclined to go to Plan B, which is a stored
procedure that accomplishes essentially the same thing and is probably
a bit faster and more secure.  I have one bug with the SP that I need
to work out, and may bring it before this forum if I can't get it
solved on my own.

As you requested, here is the complete code for the proximity search
with multiple filters that derive from the specific appended query
parameters.  It runs fine and allows all 6 filters to work quite
well.  However it doesn't have the ORDER BY clause in the query:

Private Sub btnProximitySearch_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles btnProximitySearch.Click
       Dim SearchTerm1
       SearchTerm1 = txtProximitySearch1.Text
       Dim SearchTerm2
       SearchTerm2 = txtProximitySearch2.Text

       Dim Connection As New SqlConnection(DataSource)
       Dim command As New SqlCommand()
       command.Connection = Connection
       Dim myQuery As New System.Text.StringBuilder()
       myQuery.Append("SELECT FullDocuments.FullDocNo,
FullDocuments.DocType, Details.YearGiven FROM FullDocuments INNER JOIN
Details ON FullDocuments.FullDocNo = Details.FullDocNo WHERE 1 = @p1
AND CONTAINS (SectionText, ' """ & SearchTerm1 & """ NEAR """ &
SearchTerm2 & """ ')")

       Dim p1 As New SqlParameter("@p1", 1)
       command.Parameters.Add(p1)

       If cmbProximityDocType.SelectedIndex > 0 Then
           myQuery.Append(" AND DocType = @p2")
           Dim p2 As New SqlParameter("@p2", SqlDbType.VarChar, 10)
           p2.Value = cmbProximityDocType.Text.ToString
           command.Parameters.Add(p2)
       End If

       If Not txtProximityYear.Text.Length = 0 Then
           myQuery.Append(" AND YearGiven = @p3")
           Dim p3 As New SqlParameter("@p3", SqlDbType.SmallInt)
           p3.Value = txtProximityYear.Text.ToString
           command.Parameters.Add(p3)
       End If

       If cmbProximitySex.SelectedIndex > 0 Then
           myQuery.Append(" AND Sex = @p4")
           Dim p4 As New SqlParameter("@p4", SqlDbType.VarChar, 10)
           p4.Value = cmbProximitySex.Text.ToString
           command.Parameters.Add(p4)
       End If

       If cmbProximityCategory.SelectedIndex > 0 Then
           myQuery.Append(" AND Category = @p5")
           Dim p5 As New SqlParameter("@p5", SqlDbType.NVarChar, 10)
           p5.Value = cmbProximityCategory.Text.ToString
           command.Parameters.Add(p5)
       End If

       If cmbProximityAgeCat.SelectedIndex > 0 Then
           myQuery.Append(" AND AgeCat = @p6")
           Dim p6 As New SqlParameter("@p6", SqlDbType.VarChar, 10)
           p6.Value = cmbProximityAgeCat.Text.ToString
           command.Parameters.Add(p6)
       End If

       If Not txtProximityAgeNum.Text.Length = 0 Then
           myQuery.Append(" AND AgeNum = @p7")
           Dim p7 As New SqlParameter("@p7", SqlDbType.SmallInt)
           p7.Value = txtProximityAgeNum.Text.ToString
           command.Parameters.Add(p7)
       End If

       command.CommandText = myQuery.ToString
       Dim da As New SqlDataAdapter(command)
       Dim ds As New DataSet()

       Try
           Connection.Open()
           Cursor = Cursors.WaitCursor()
           da.Fill(ds)
       Catch ex As Exception
           MessageBox.Show(ex.Message)
       Finally
           Connection.Close()
           Cursor = Cursors.Default

       End Try

       If ds.Tables.Count > 0 Then
           datProximityResults.DataSource = ds.Tables(0)
       Else
           datProximityResults.DataSource = Nothing
       End If

End Sub