"There is no method with the name"

Hey Guys…

I’m trying to be clever and I came up with a nice formula to solve my navigation problem… here is the peice of code that is meant to bring it all together:

 on (press) {
 _root.current+"_button".submenu.gotoAndPlay("out");
} 

but I keep getting this error:

 **Error** Symbol=home_nav, layer=invisible, frame=1:Line 16: There is no method with the name 'submenu'.
	 _root.current+"_button".submenu.gotoAndPlay("out");
Total ActionScript Errors: 1 Reported Errors: 1 

You any of you be so kind as to let me know how I can execute this line of code properly?

Thank you in advance!

l2eDsanD