function checkSelection(){

player1Index = document.form.player1.selectedIndex;
player1SelectedName = document.form.player1.options[player1Index].nametag;



player2Index = document.form.player2.selectedIndex;
player2SelectedName = document.form.player2.options[player2Index].nametag;

if (player1Index == player2Index) {
alert ("Vous devez comparer deux joueurs différents.");
return false;
} else {

document.form.player1Name.value = player1SelectedName;
document.form.player2Name.value = player2SelectedName;

document.form.submit();
} // end of if

} // end of function