For basic query selector
var me = _qSelector("#btn_test");
For query selector only 1 class for change background colour
_qSelectorBackgroundCol(".my_class",flat_ui_color.alizarian);
For query selector all of element with the same class for change background colour
_qSelectorBackgroundCol(".my_class",flat_ui_color.alizarian,true);
Hello World 1
Hello World 2
Hello World 3
Hello World 4
Hello World 5
or for query selector inner HTML by id of element
_qSelectorHTML("#my_div",_randomStr(15));