c# - Text boxes Not changing after selecting from dropdown list -

my web page should allow me select title of book drop-down list, press select button, , textboxes(ie. author, year, category) should change according book selected. however, when select second book list, loops show details of 1st book on dropdown list, no matter select, shows first record.

here code:

  protected void page_load(object sender, eventargs e) {     loaddetails(); }  private void loaddetails() {     sqlconnection conn;     sqlcommand comm;     sqldatareader reader;     string connectionstring =configurationmanager.connectionstrings["database"].connectionstring;     conn = new sqlconnection(connectionstring);     comm = new sqlcommand("select bookid, title books", conn);     try     {         conn.open();         reader = comm.executereader();         ddlsearch.datasource = reader;         ddlsearch.datavaluefield = "bookid";         ddlsearch.datatextfield = "title";         ddlsearch.databind();         reader.close();     }      catch     {         lblerror.text = "error loading books";     }      { conn.close(); } } protected void btnsearch_click(object sender, eventargs e) {     sqlconnection conn;     sqlcommand comm;     sqldatareader reader;     string connectionstring =configurationmanager.connectionstrings["database"].connectionstring;     conn = new sqlconnection(connectionstring);     comm = new sqlcommand("select isbn, author, title, year, category books bookid=@bookid", conn);     comm.parameters.add("@bookid", system.data.sqldbtype.int);     comm.parameters["@bookid"].value = ddlsearch.selecteditem.value;     try     {         conn.open();         reader = comm.executereader();         if (reader.read())          {             txtisbn.text = reader["isbn"].tostring();             txtauthor.text = reader["author"].tostring();             txttitle.text = reader["title"].tostring();             txtyear.text = reader["year"].tostring();             txtcat.text = reader["category"].tostring();          }     }       catch     {         lblerror.text = "error laoding pages";     }          {         conn.close();      } } 

i've tried many different variations of code doesnt seem working. simple enough fix can't put finger on it. appreciated. thanks!

your problem in page_load, btnsearch_click event fired after enter page_load event , since didn't check if page posts reload details again, solvethe problem:

protected void page_load(object sender, eventargs e) {     if(!ispostback)     loaddetails(); }