use drop down value to run query without submit - sql

Question

<form name = "rsPass" action="<%= pagePath %><%= jspPageName %>.jsp?callrspassthru=true" method="post">
<table cellpadding="0" cellspacing="0" width="640">
<tr>
<td class="wizardHeader" width="100%" style="height: 21px;"> FCAT Scores by Teacher by Course with Gains and Years Growth</td>
</tr>
<tr>
<td class="wizardInstruction" style="padding-top: 10px; padding-right: 30px; padding-left: 30px; height=33px;"valign="top">
<br>
This report will list all teachers, courses, and student's FCAT scores with gains.
<br><br>
</td>
</tr>
<tr>
<td width="100%" height="2" background="images/hr.gif"><IMG height="2" src="images/hr.gif"></td>
</tr>
<table width="700">
<tr>
<td class="detailFormColumn"><br>
<label>Active or Inactive Teachers: </label><br>
<select name="active">
<option value=""> Select <br> </option>
<option value="IS NULL"> Active <br> </option>
<option value="IS NOT NULL">Inactive <br> </option>
</select>
</td>
</tr>
First letter of teacher's last name:
<%
out.println(request.getParameter("active"));
// both of these values are NULL as if they are not being read when the drop down is selected above
Statement db1 = con.createStatement();
int newRecords1 = 0;
SQL1 = " SELECT DISTINCT substring(i.lastName, 1, 1) as grade " +
" FROM employmentAssignment e with(nolock) " +
" JOIN calendar c with(nolock) on c.schoolID = e.schoolID " +
" JOIN person p with(nolock) on p.personID = e.personID " +
" JOIN [identity] i with(nolock) on i.identityID = p.currentIdentityID and i.personID = p.personID " +
" WHERE c.calendarID = " + calID + "" +
" AND e.enddate is " + request.getParameter("active") + "" +
" AND e.teacher = 1 " +
" ORDER BY substring(i.lastName, 1, 1) ";
result1 = db1.executeQuery(SQL1);
out.println("<select name=grade id=15 onchange='loadStudents()'><option value='NULL' selected='true'>Select</option>");
while(result1.next()) { grade=result1.getString(1); out.println("<option value='"+grade+"'>"+grade+"</option>");}
out.println("</select>");
con.close();
%>