div wont show up inside another div - html

Question

I am trying to get two divs to sit side by side within another div, however the first div won't show up in the container div. "contactleft" wont show up inside of "contactcont". I'm not sure if it has something to do with the display:block's or not? I tried clearing the "left" one too, no luck. Anyone know whats up? Thank you!
html:
<div id="contact">
<img src="Images/contactbanner.jpg" alt="contactbanner">
</div>
<div id="contactcont">
<div id="contleft">
</div>
</div>
CSS:
#contactleft {
float:left;
display:block;
background-color:red;
width:100px;
height:300px;
}
#contactcont {
display:block;
clear:both;
background-color:blue;
height:350px;
width:960px;
margin-left:auto;
Margin-right:auto;
}

Answer 1

You have what I assume is a typo in your code. Should work correctly with the following:
<div id="contactcont">
<div id="contactleft">
</div>
</div>
See jsfiddle

Answer 2

You have a typo at contleft in your CSS it should be :
#contleft {
float:left;
display:block;
background-color:red;
width:100px;
height:300px;
}
Your HTML looks fine :
<div id="contactcont">
<div id="contleft">
inner content here
</div>
</div>
Here is the fiddle showing that.

Answer 3

You're actually pretty good there, I would just change your "contactLeft" to a class, and repeat "contactLeft" as many times as you need to. Here's a link to a CodePen.
Link to CodePen
Here's the HTML:
<div id="contactCont">
<p>contact Container</p>
<div class="contleft">
<p>contact Left</p>
</div>
<div class="contleft">
<p>contact Left</p>
</div>
</div>
And here's the CSS:
.contleft {
float:left;
display:block;
background-color:red;
width:100px;
height:300px;
border: 1px solid black;
margin-left:1px;
}
#contactCont {
display:block;
clear:both;
background-color:blue;
height:350px;
width:960px;
margin-left:auto;
Margin-right:auto;
}
Note, that I changed your banner height to 20px and stretched the screen width.
Then I just copied your second "div" inside your container in the same hierarchy to add another side by side. I added 1px of margin-left, and 1px solid black borders to exaggerate the point.
You can also reference bootstrap for some responsive sizings if you're new to this until you get to understanding the CSS and HTML elements a little more.
Get BootStrap