how to trigger tab event in javascript code example

Example 1: javascript press tab key

window.onkeypress = function(e) {
    if (e.which == 13) {
       e.preventDefault();
       var nextInput = inputs.get(inputs.index(document.activeElement) + 1);
       if (nextInput) {
          nextInput.focus();
       }
    }
};

Example 2: javascript press tab key

window.onkeypress = function(e) {
    if (e.which == 13) {
        e.preventDefault();
        var inputs = document.getElementsByClassName('input');
        for (var i = 0; i < inputs.length; i++) {
        if (document.activeElement.id == inputs[i].id && i+1 < inputs.length ) {
            inputs[i+1].focus();
            break;   
        }
    }