How To DeleteDuplicateRecord From ArrayList

ar is ArrayList int index; for(int i=0; i<(ar.Count-1); i++) { index=ar.IndexOf(ar[i], i+1); while( index>i ) { ar.RemoveAt(index); if( i<(ar.Count-1) ) { index=ar.IndexOf(ar[i], i+1); } else { index=-1; } } }