Focus MainTextBox on load with backspace functionality

MainTextBoxWithBckSpace

window.onload = function () {
// focus on the input field for easy access...
var input = document.getElementById ('focusme');
input.focus ();
// ...but if someone wishes to go back in their history, let them!
document.onkeydown = function (e) {
if (!e) {
var e = window.event;
}
if (e.keyCode === 8 && !input.value) {
history.back();
}
};
};