press a button in imacros using javascript if its id is different

I was trying to do a little javascript to press a button that changes id, that is to say every time I reload the page the button changes from id but it never presses me. The code is as follows:

var string = '';
var letters = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','Ñ','O','P','Q','R','S','T','U','V','W','X','Y','Z'];
var init_macro = "CODE:";
init_macro += "VERSION BUILD=9052613" + "\n";
init_macro += "SET !ERRORIGNORE YES" + "\n";
for(i = 0; i < 54; i++){
string += letters[i];

init_macro += "TAG POS=1 TYPE=A ATTR=letters{{string}}*" + "\n";
iimPlay(init_macro);
}

The button usually starts with a letter and I put an asterisk followed by the combination of letters I have but never select my button.