A modern cross-platform JavaScript library & only 18 bytes
...or just 10 bytes minified
$.getElementById("demo1").addEventListener('click', function(){
alert('click');
});
console.log("Height: "+$.body.clientHeight);
console.log("Width: "+$.body.clientWidth);
More examples and documentation can be found here.
Sure... I built diy.js because I wanted the flexibility to do anything but without the expensive weight of other JavaScript libraries.
I've been developing diy.js for three years, about nine months of this was ensuring that diy.js was fully browser tested.
Testing is vital when you are running in many different environments. Thats why diy.js has 100% test coverage check it out.
It's right here — have fun.