OK, the script creates new input box onclick. How can I get it to show up above the button? I am confused on insertBefore();

<div id="newcourses" style="text-align:left;">
<input name="add_students" type="button" class="submit" onClick="add_student()" value="Add More Students"></div>


function add_student(){

//// Create Line breaks ////
var linebreak=document.createElement("p");
var linebreak0=document.createElement("p");

//// Create text ////
var header = document.createTextNode("Student Information");
var firstname_text = document.createTextNode("First Name: ");

//// Create input boxes ////
var StudentFirstname=document.createElement('input') ;
StudentFirstname.type='text';
StudentFirstname.size='45';
StudentFirstname.name='Student2_Firstname';

//// Append ////
document.forms.Registration.appendChild(header);
document.forms.Registration.appendChild(linebreak0 );
document.forms.Registration.appendChild(firstname_text);
document.forms.Registration.appendChild(StudentFir stname);
}