[FMX] calling the same function twice

the who.say in the following function refers to a var displayed inside a dynamic text box.

when I tryed to call the function twice, from the same MC, only with different Who’s and What’s, it didn’t work. only one call displayed the text. any idea why?

//who is talking, what is he saying, and for how long his text is displayed*
function saythat(who, what, fortime) {
starttime = getTimer();
this.onEnterFrame = function() {
if (getTimer() - starttime < fortime) {
who.say = what;
else {
who.say = “”;
delete this.onEnterFrame;

huge thanks!