c# - dropdown initializing input type="text" on postback -

i have several text boxes <input type="text"> a dropdownlist<asp:dropdownlist> prefer use asp control want bind data. thing every time make selection text boxes re-initializes due post back.

<asp:dropdownlist id="drppleaseselect" runat="server" onselectedindexchanged="drppleaseselect_selectedindexchanged" autopostback="true" >                     <asp:listitem>[please select yes or no]</asp:listitem>                     <asp:listitem>yes</asp:listitem>                     <asp:listitem>no</asp:listitem>                 </asp:dropdownlist>  <input type="text" runat="server" id="txtlastname" onkeyup="checktextboxes()" onfocus="checktextboxes()" />  protected void drppleaseselect_selectedindexchanged(object sender, eventargs e) {     var valuedropdown = drppleaseselect.selectedvalue.tostring();     if (valuedropdown == "[please select yes or no]")     {         labchkdropdown.innerhtml = "please select yes or no";     }     else if (valuedropdown == "yes" || valuedropdown == "no")     {         //bind different asp:dropdownlist database data     } } 

is there way html text boxes not affected postback make changes index of dropdown list?

you said every time make selection text boxes re-initialize, setting them on pageload or function called pageload?

if case think missing check ispostback:

protected void page_load(object sender, eventargs e) {   if (!ispostback)   {     //do stuff want done on inital page load.     //like setting inital values in textboxes, etc.   } }