insert textbox entry into query

I am new to this a need to update a page that I did not code. What I need to
do is take the value entered into a textbox and add it to a query. The user
would enter somthing like %value% (% being wildcard) into the text box and
then click a search button. This would then add this value to the query. I
know the sql just do not know how to add to the query. The db is Oracle.
Hope this makes sense. Part of the code is below.

<form action="time_to_project_by_project_number-dynamic.asp" method="POST"
name="parmform">
<table border="1">

<tr>
<td>Project Number Search:</td>
<td>
<input id="txtSearch" type="text" />
<input id="btnSearch" type="button" value="Search" />
</td>

</tr>
<tr>
<td>Select Project Number(s):
</td>
<td>

<%
parmid = "P1"
provider = "MSDASQL"
datasource = "dbname"
username = "username"
password = "password"
databasetable = "tablename"
valuedatabasecolumn = "columnname"

strConn = "Provider=" & provider & ";Data Source=" & datasource & ";User
ID=" & username & ";password=" & password & ";"

query = "SELECT DISTINCT " & valuedatabasecolumn & "," & valuedatabasecolumn
& " || ' - ' || description "
query = query & " FROM " & databasetable
query = query & " where POST_DATE >= to_date('01/01/2007', 'MM/DD/YYYY')"

txtSearch=request.form("txtSearch")

set conn = Server.CreateObject("ADODB.Connection")
conn.Open strconn
set rs = conn.Execute( query )

Response.Write("<SELECT SIZE=15 NAME=" & chr(34) & parmid & chr(34) &
" MULTIPLE>" & chr(13) )
rs.movefirst
do while not rs.EOF
if rs(0) <> "" then
Response.Write( "<OPTION VALUE=" & chr(34) & rs(0) & chr(34) &
">" & rs(1) & chr(13) )
end if
rs.movenext
loop
Response.Write("</SELECT>")

rs.close
set rs = nothing
set conn = nothing
%>

.