Confirmation box troubles

[BlueMelon]

function WarpAIS_Button.onAction(){

confirm("WarptoAIS");
if(this.flag ==1){
this.chat = "test";
}else if (this.flag == 0)
{
this.chat = "no";
}
}



function confirm(action){
this.flag = 0;
	new GuiWindowCtrl("ConfirmationBox"){
		profile = "GuiBlueWindowProfile";
		width = 131;
		height = 110;
		x = player.x;
		y = player.y;
		text = "Confirmation";
		canMaximize=false;
		canMinimize=false;
		destroyonhide=true;
		canresize = false;

	new GuiTextCtrl("AlertConfirm_l") {
	  profile = GuiBlueTextProfile;
	  x = 11;
	  y = 27;
	  height = 15;
	  width = 130;
	  text = "Proceed with:";
	}

	new GuiTextCtrl("AlertConfirm_l_action") {
	  profile = GuiBlueTextProfile;
	  x = 30;
	  y = 42;
	  height = 15;
	  width = 130;
	  text = action;
	}

	new GuiButtonCtrl("cYes_Button") {
	   profile = GuiBlueButtonProfile;
	   x = 11;
	   y = 67;
	   width = 50;
	   height = 30;
	   text = "Yes";
	 }

	new GuiButtonCtrl("cNo_Button") {
	   profile = GuiBlueButtonProfile;
	   x = 71;
	   y = 67;
	   width = 50;
	   height = 30;
	   text = "No";
	 }

	}
}

function cYes_Button.onAction()
{
ConfirmationBox.destroy();
this.flag = 1;
}
function cNo_Button.onAction()
{
ConfirmationBox.destroy();
this.flag = 0;
}

Here is a snippet of a script I created. The problem is, when I click the WarptoAIS button, yes the confirmation box does popup, but the value that the WarpAIS_Button.onAction() is always false because when the confirm box is created.. How can I make a function to confirm an action before performing it?

in short...
Action --> Confirm --> If true, do action