iFrames Help!!

[Ryya]

I'm using one main iFrame with targeted navigation and it's NOT WORKING. Works in chrome, not firefox, not IE. I click a navigation link and it opens in a new tab, instead of opening in the target iframe. Heres what i'm working with:


<div id="DivHome"> <a href="arcade.php" target="mainframe"><strong><font color="white">Home</font></strong></a></div>
<div id="DivConstruction"> <a href="under_construction.php" target="mainframe"><strong><font color="white">Construction</font></strong></a></div>

and heres my iframe.


<iframe scrolling="no" SRC="arcade.php" marginwidth="0" marginheight="0" frameborder="0" vspace="0" hspace="0" width="100%" height="100%" id="_iframe">

aaand my style.css.


#DivHome {
position:absolute;
left:42px;
top:113px;
width:39px;
height:21px;
font-size: 16pt;
font-family:Tahoma, Geneva, sans-serif;
}
a {
font-size: 14px;
color: #FFF;
}
a:visited {
color: #000;
text-decoration: none;
}
a:hover {
color: #0F0;
text-decoration: underline;
}
a:active {
color: #000;
text-decoration: none;
}
a:link {
color: #FFF;
text-decoration: none;
}
body,td,th {
color: #000;
}



#DivConstruction {
position:absolute;
left:91px;
top:113px;
width:50px;
height:21px;
font-size: 16pt;
font-family:Tahoma, Geneva, sans-serif;
}
a {
font-size: 14px;
color: #FFF;
}
a:visited {
color: #000;
text-decoration: none;
}
a:hover {
color: #0F0;
text-decoration: underline;
}
a:active {
color: #000;
text-decoration: none;
}
a:link {
color: #FFF;
text-decoration: none;
}
body,td,th {
color: #000;
text-align: left;
}

Please help? I know it is something really silly, it has to be. Just can't figure it out.