Loop return false

My array consist of the below values that gather from XML:

beginbegin,endend,-,-,-,begin,end,-,-,-,begin,end,-,-,-,-,begin,-,end,-,-,-,-,begin,-,-,end,-,-,beginbegin,-,continuecontinue,

To check whether it has "beginbegin":

if(beamStatusArray[a]=="beginbegin") {}

It return false instead of true, do开发者_如何学Goesn't happen to begin or end, why it doesn't work when it has a repeat words?

where do you get your a from?
and btw there's an easier way to check if there's a value in an array:

var arr:Array = new Array('beginbegin', 'endend', '-', '-', '-', 'begin', 'end', '-', '-', '-', 'begin', 'end', '-', '-', '-', '-', 'begin', '-', 'end', '-', '-', '-', '-', 'begin', '-', '-', 'end', '-', '-', 'beginbegin', '-', 'continuecontinue');
trace(arr.indexOf('beginbegin') != -1);