Question

How to check if input=”text” value is not NULL and then move to page?

<input TYPE="text" name="textbox2" align="center">
........
function HomeButton()
                {
                    <!--if textbox1 value and textbox2 value not null-->
                        location.href="registration.html";
                }

Answer 1

Just check that both their values are truthy.

var textbox1 = document.getElementsByName('textbox1')[0];
var textbox2 = document.getElementsByName('textbox2')[0];

if(textbox1.value && textbox2.value) {
    location.href = "registration.html";
}

---

Of course, you can make things easier by giving them ids:

<input type="text" name="textbox2" id="textbox2" align="center">

and

var textbox2 = document.getElementById('textbox2');

for example.