dynamically populate textbox with database values when value is select

hi can u pls solve my problem

i want to populate a combobox from mysql db and i want that suppose i select an option the related data of other columns of the same table should be displayed in text box.i am using jsp and mysql.

%String CategoryCombo = null;
%>
<%while(rs.next())
{
CategoryCombo = rs.getString("emp_name");%>
<%<%out.println(CategoryCombo)%>

%>
<%}%>

<%String viewText=null;%>
<% rs1=stmt.executeQuery("select * from emp where emp_name='"+CategoryCombo+"');%>
<%while(rs1.next())
{
viewText=rs1.getString("emp_job");%>
Emp jod id="empdes" readonly=true>
<%}%>

when i write this code the combo box is populated but i get problem in the where conditon and also i do not get data in the text box.please provide me with a solution.