When i dowload firefox i go to maplestory it said clike here to dowlaod plugin And when i did it said that?

Adobe flash player not avalible Then there is place it said manual install i clike their i try to dowlad adobe flash it said That firefox must be close before Adobe fash player plugin can be installed. And if i did that my game maplestory wount work. when i dowload it. my game page is blank i dont know what to do """"'plz Hlp Hlp"""