asp.net - .NET C# DropDownList pass parameter to function -

i don't know how word this...i have drop down list queries database , displays list of descriptions based on ids. want user able select description, push button , call getqueryresults() function id being passed , not description. getqueryresults(dropdownlist1.selectedvalue) doesn't work because of conflicting types. else can use?

    protected void page_load(object sender, eventargs e)     {         dataconnector dc = new dataconnector();         dropdownlist1.datasource = dc.getcodetypes();         dropdownlist1.datavaluefield = "id";         dropdownlist1.datatextfield = "description";         dropdownlist1.databind();     }      protected void button1_click(object sender, eventargs e)     {         dataconnector dc = new dataconnector();         gridview2.datasource = dc.getqueryresults(dropdownlist1.selectedvalue); //error: cannot convert string int         gridview2.databind();      }      public list<codedesc> getqueryresults(int searchterm)     {         try         {             string query = "select id, code, descr code_desc code_type_id = :searchterm";            //more stuff 

my manager not want me change query string. (previously had used "select id, code, descr code_desc code_type_id = (select id code_desc descr = :searchterm);" searchterm string description eliminating need id)

start wrapping dropdownlist databinding inside ispostback check.

if (!page.ispostback) {     dropdownlist1.datasource = dc.getcodetypes();     dropdownlist1.datavaluefield = "id";     dropdownlist1.datatextfield = "description";     dropdownlist1.databind(); } 

i not, every time load page data bound again , dropdownlist goes it's first value.

then can call getqueryresults selectedvalue converting value int.

gridview2.datasource = dc.getqueryresults(convert.toint32(dropdownlist1.selectedvalue)); 

finally, google parameratized queries.