.net - Ranking Priority using DropDownList in C# -

my idea build ranking priority using dropdownlist asp server control.

here's setup: have 3 dropdownlists , has 3 items ("first", "second", "third") on each dropdownlists. when have chosen 1st dropdownlist assuming item have selected "first" , on 2nd dropdownlist default selecteditem "first" item of 1st dropdownlist on have selected must swapped on 2nd dropdownlist.

in short there unique selecteditems on each dropdownlist , in every selectedindexchanged event occuring there swapping of items on 3 dropdownlists. that's ranking priority be.

my question be, how can swapped previous item on dropdownlist going 1 dropdownlist have selected on , placed new item?

here's code:

protected void dropdownlistpriority_selectedindexchanged(object sender, eventargs e) {     dropdownlist ddlrank = (dropdownlist)sender;      int swapindex;     string sameddlselecteditemid;           //get list of ddls         list<dropdownlist> ddlranklist = new list<dropdownlist>();         ddlranklist.add(ddlbiometricnoorder);         ddlranklist.add(ddldatetimeorder);         ddlranklist.add(ddltransactiontypeorder);          //store listitems ddl         list<string> strranklist = new list<string>();         strranklist.add("first");         strranklist.add("second");         strranklist.add("third");          //holds temp. ddl         list<dropdownlist> tempranklist = new list<dropdownlist>();          //remove '<-- select -->' item when ddl changed         if(ddlrank.items.contains(new listitem("<-- select -->")))             ddlrank.items.removeat(0);                          //loop on each list<t>         for(int x = 0; x < ddlranklist.count; x++)         {             (int y = 0; y < ddlranklist.elementat(x).items.count; y++)             {                 if (ddlranklist.elementat(x).items[y].text != ddlrank.selecteditem.text)                 {                     //check amongst unselected item changed (int swapindex)                     swapindex = convert.toint32(ddlranklist.elementat(x).items[y].value);                 }             }         }          foreach (dropdownlist ddl in ddlranklist)         {             foreach (string strrank in strranklist)             {                 if (ddlrank.selecteditem.text == ddl.selecteditem.text)                 {                     sameddlselecteditemid = ddl.id;                      //set ddl selectedindex                     ddl.selectedindex = //this question;                  }             }         }  } 

i see have considered approach lists repopulated @ server end. there specific reason server postbacks costly. instead why don't consider jquery/javascript based solution lists manipulated based on user selected values.

you can implement event based model well. refer this