drop down menu align in a single line - html

Question

I have made three drop down menu. I want to align one after the other. Below is the code I am using. But its not coming in the same line. What I want is first should go on left, second should go on center and third should go on right.
First is
<div style="float:left;">
<FORM name="mapform" method="POST">
<SELECT name="jump" size="1">
<OPTION value="" SELECTED>Select the Category</option>
<OPTION value="http://www.fe dri.com/posting.php?mode=post&f=1">Ask a Question</option>
<OPTION value="http://www.fe dri.com/posting.php?mode=post&f=4">Vehicle for Sale</option>
</SELECT>
<INPUT type=button onClick= "location = '' + document.mapform.jump.options[ document.mapform.jump.selectedIndex ].value;" value="Place an Ad!">
</FORM>
</div>
Second is
<div style="float:center;">
<FORM name="mapform2" method="POST">
<SELECT name="jump2" size="1">
<OPTION value="" SELECTED>Select the Category</option>
<OPTION value="http://www.fe dri.com/discuss">General Discussion</option>
</SELECT>
<INPUT type=button onClick= "location = '' + document.mapform2.jump2.options[ document.mapform2.jump2.selectedIndex ].value;" value="Quick View !">
</FORM>
</div>
Third is
<div style="float:right;">
<FORM name="mapform1" method="POST">
<SELECT name="jump1" size="1">
<OPTION value="" SELECTED>Select the Category</option>
<OPTION value="http://www.fe dri.com/posting.php?mode=post&f=16">Start New General Discussion</option>
<OPTION value="http://www.fe dri.com/posting.php?mode=post&f=28">Start New Event</option>
</SELECT>
<INPUT type=button onClick= "location = '' + document.mapform1.jump1.options[ document.mapform1.jump1.selectedIndex ].value;" value="Start a Discussion!">
</FORM>
</div>
I am getting it as in the image

Answer 1

There is no float:center. Float your first two divs left, and the last one right. This should fix the problem, assuming you have enough space for all your elements on one line.
Here is a demonstration: http://jsfiddle.net/MCRUX/
In case you missed it in the example, I have set the width of each of the container divs to 30%:
<div style="float:left;width:30%;">

Answer 2

Use a table having 3 columns to align the drop down box.
<table width="100%">
<tr>
<td align="left">{drop down box 1}</td>
<td align="center">{drop down box 2}</td>
<td align="right">{drop down box 3}</td>
</tr>
</table>

Answer 3

As #Asad said, there is nothing called float:center. If the size of the parent element in which you are placing your divs has a fixed size, you can do some mathematical calculation and decide the size of the divs you are gonna place.
for example, if i have a parent box of 960px and want to place 3 divs inside it, i ll do something like this...
div.children {
width:313.33px;
margin-right:10px;
float:left;
}
div.children:last-child {
margin-right:0;
}
Since 313.33 X 3 ~ 940 plus total margin will be 20px and both will add upto 960px.