function part2() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part2.className == 'hidden' ) {
part2.className = 'visible';
part3.className = 'hidden';
part4.className = 'hidden';
part5.className = 'hidden';
part6.className = 'hidden';
part7.className = 'hidden';
} else {
part2.className = 'hidden';
}
}

function part3() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part3.className == 'hidden' ) {
part2.className = 'hidden';
part3.className = 'visible';
part4.className = 'hidden';
part5.className = 'hidden';
part6.className = 'hidden';
part7.className = 'hidden';
} else {
part3.className = 'hidden';
}
}

function part4() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part4.className == 'hidden' ) {
part2.className = 'hidden';
part3.className = 'hidden';
part4.className = 'visible';
part5.className = 'hidden';
part6.className = 'hidden';
part7.className = 'hidden';
} else {
part4.className = 'hidden';
}
}

function part5() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part5.className == 'hidden' ) {
part2.className = 'hidden';
part3.className = 'hidden';
part4.className = 'hidden';
part5.className = 'visible';
part6.className = 'hidden';
part7.className = 'hidden';
} else {
part5.className = 'hidden';
}
}

function part6() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part6.className == 'hidden' ) {
part2.className = 'hidden';
part3.className = 'hidden';
part4.className = 'hidden';
part5.className = 'hidden';
part6.className = 'visible';
part7.className = 'hidden';
} else {
part6.className = 'hidden';
}
}

function part7() {
var part2 = document.getElementById('part2');
var part3 = document.getElementById('part3');
var part4 = document.getElementById('part4');
var part5 = document.getElementById('part5');
var part6 = document.getElementById('part6');
var part7 = document.getElementById('part7');
if ( part7.className == 'hidden' ) {
part2.className = 'hidden';
part3.className = 'hidden';
part4.className = 'hidden';
part5.className = 'hidden';
part6.className = 'hidden';
part7.className = 'visible';
} else {
part7.className = 'hidden';
}
}