Form Div breaks parent div and wraps - html

Question

I really need your help with this. For the life of me, I cannot begin to understand as to why I cannot seem to get my form DIV to properly be positioned on the right side of my 2 column layout.
See attached picture below:
Here is the HTML & CSS in question:
* {
font-family: Segoe UI;
font-size: 9pt;
}
html, body {
padding: 0;
margin: 0;
}
body {
background: rgb(187,195,203);
}
.Absolute-Center {
margin: auto;
}
#wrapper {
position:absolute;
top:50%;
left:50%;
transform: translate(-50%,-50%);
}
#layout {
height: auto;
width: 900px;
border: 1px solid rgb(112,112,112);
}
#box1 {
background: rgb(141,155,169);
color: #FFF;
padding: 3px;
font-weight: bold;
}
#box2 {
width: 100%;
background: rgb(240,240,240);
border-bottom: 1px solid rgb(180,180,180);
padding: 4px;
box-sizing: border-box;
}
#box3 {
width: 100%;
border-bottom: 1px solid rgb(180,180,180);
}
#box4 {
background: #FFF;
float: left;
width: 175px;
height: 375px;
border-right: 1px solid rgb(180,180,180);
}
#box5 {
background: rgb(240,240,240);
height: 375px;
}
#box7 {
background: rgb(240,240,240);
padding: 5px;
text-align:center;
}
#leftcolumn {
float: left;
}
#rightcolumn {
border: 0;
padding: 3px;
text-align: center;
}
.clear {
clear: both;
}
fieldset {
margin: 0;
padding: 2px;
padding-bottom: 5px;
}
div.wrapper {
width: 500px;
}
div.form {
width: 100%;
background-color: rgb(240,240,240);
border: 1px sold #000;
padding: 5px;
}
div.row {
clear: both;
padding-top: 5px;
}
div.row span.label {
float: left;
width: 50px;
text-align: right;
padding-right: 5px;
}
div.row span.formw {
float: left;
width: 200px;
text-align: left;
}
div.spacer {
clear: both;
}
span.title {
color: rgb(70,141,180);
}
input {
width: 150px;
border: 1px solid #000;
}
<div id="wrapper">
<div id="layout" class="Absolute-Center">
<div id="box1">Application Title</div>
<div id="box2">
<div id="leftcolumn"></div>
<div id="rightcolumn"></div>
<div class="clear"></div>
</div>
<div id="box3">
<!-- LEFT WINDOW PANE -->
<div id="box4">
<div id="menu_wrapper">
<ul id="menu">
<li data-show="#1">File Information</li>
<li data-show="#2">Comments</li>
</ul>
</div>
</div>
<!-- RIGHT WINDOW PANE -->
<div id="box5">
<!-- CONTENT [TAB1] -->
<div id="1" style="width: 100%;" class="hidden tab">
<div class="form">
<form>
<div style="border-bottom: 1px solid #000;" class="row"><span class="title">FILE INFORMATION</span></div>
<div class="row">
<span><b>Date Received</b></span>
</div>
<div class="row">
<span class="label">From:</span><span class="formw"><input type="text"/></span>
</div>
<div class="row">
<span class="label">To:</span><span class="formw"><input type="text"/></span>
</div>
<div class="spacer"></div>
</form>
</div>
</div>
<!-- CONTENT [TAB2] -->
<div id="2" class="hidden tab"></div>
</div>
</div>
</div>
</div>

Answer 1

I got it to sit in the right container by adding float:right to the form container div
Fiddle - http://jsfiddle.net/90777hu9/

Answer 2

It's because you float box4 left but you do not float box5 right. So it is still in the flow of the document and pushed below the float left.

Answer 3

Added float:left and width: 78%; to .box5 Press in the snippet the fullpage button to see it
* {
font-family: Segoe UI;
font-size: 9pt;
}
html, body {
padding: 0;
margin: 0;
}
body {
background: rgb(187,195,203);
}
.Absolute-Center {
margin: auto;
}
#wrapper {
position:absolute;
top:50%;
left:50%;
transform: translate(-50%,-50%);
}
#layout {
height: auto;
width: 900px;
border: 1px solid rgb(112,112,112);
}
#box1 {
background: rgb(141,155,169);
color: #FFF;
padding: 3px;
font-weight: bold;
}
#box2 {
width: 100%;
background: rgb(240,240,240);
border-bottom: 1px solid rgb(180,180,180);
padding: 4px;
box-sizing: border-box;
}
#box3 {
width: 100%;
border-bottom: 1px solid rgb(180,180,180);
}
#box4 {
background: #FFF;
float: left;
width: 175px;
height: 375px;
border-right: 1px solid rgb(180,180,180);
}
#box5 {
background: rgb(240,240,240);
height: 375px;
float:left;
width: 78%;
}
#box7 {
background: rgb(240,240,240);
padding: 5px;
text-align:center;
}
#leftcolumn {
float: left;
}
#rightcolumn {
border: 0;
padding: 3px;
text-align: center;
}
.clear {
clear: both;
}
fieldset {
margin: 0;
padding: 2px;
padding-bottom: 5px;
}
div.wrapper {
width: 500px;
}
div.form {
width: 100%;
background-color: rgb(240,240,240);
border: 1px sold #000;
padding: 5px;
}
div.row {
clear: both;
padding-top: 5px;
}
div.row span.label {
float: left;
width: 50px;
text-align: right;
padding-right: 5px;
}
div.row span.formw {
float: left;
width: 200px;
text-align: left;
}
div.spacer {
clear: both;
}
span.title {
color: rgb(70,141,180);
}
input {
width: 150px;
border: 1px solid #000;
}
<div id="wrapper">
<div id="layout" class="Absolute-Center">
<div id="box1">Application Title</div>
<div id="box2">
<div id="leftcolumn"></div>
<div id="rightcolumn"></div>
<div class="clear"></div>
</div>
<div id="box3">
<!-- LEFT WINDOW PANE -->
<div id="box4">
<div id="menu_wrapper">
<ul id="menu">
<li data-show="#1">File Information</li>
<li data-show="#2">Comments</li>
</ul>
</div>
</div>
<!-- RIGHT WINDOW PANE -->
<div id="box5">
<!-- CONTENT [TAB1] -->
<div id="1" style="width: 100%;" class="hidden tab">
<div class="form">
<form>
<div style="border-bottom: 1px solid #000;" class="row"><span class="title">FILE INFORMATION</span></div>
<div class="row">
<span><b>Date Received</b></span>
</div>
<div class="row">
<span class="label">From:</span><span class="formw"><input type="text"/></span>
</div>
<div class="row">
<span class="label">To:</span><span class="formw"><input type="text"/></span>
</div>
<div class="spacer"></div>
</form>
</div>
</div>
<!-- CONTENT [TAB2] -->
<div id="2" class="hidden tab"></div>
</div>
</div>
</div>
</div>