problems with an if statement

alright here it is guys:function popLoop ( popArray, tracerArray ) {
for( n = 0 ; n < popArray.length ; n++){
trace(popArray.length);
trace(n);
if (n = popArray.length){
trace("sure");
}
}
}

popArray.length = 3 FYI

so whats happening is i want the for statement to run through "popArray.length" [3] times.
the for loop contains commands to duplicate movies but the thing is it stops after the ending if statement...

does anyone know why the if statement stops the for loop???