javascript - Element destination

I created a html page and inserted a textbox. I would like to know a textbox destination in the page from javascript function? Example textbox's top is 100 px like that. Thank you.

Answer

Try this:

window.onload = function() {

    console.log(document.getElementById("id1").offsetTop);
};

where id1 is the id of the textbox you need to triangulate.