Others problem with dropdown list alignment plz help

hello,
i have a problem with dropdown list alignment in this page. this is the code

<div id="dropdown">
<span style="line-height:25px;">Cardholder Name</span>
<br />

<span style="line-height:25px;">Card Type</span><br />
<span style="line-height:25px;">Card Number</span><br />
<span style="line-height:25px;">Expiration Date</span><br />
<span style="line-height:25px;">Security Code</span>
<div style="position:absolute; margin-left:50px; margin-top:50px; left: 513px; top: 211px; line-height:25px; bottom: 318px; width:400px;">
<input name="textfield23" type="text" id="textfield23" size="4" maxlength="8" class="inp" style="width: 101px; " />
<br />
<input name="textfield28" type="text" id="textfield28" size="4" maxlength="8" class="inp" style="width: 101px; " />
<br />
<input name="textfield29" type="text" id="textfield29" size="4" maxlength="8" class="inp" style="width: 101px; " />
<br />

<aspropDownList class="inp" style="width: 101px; " runat="server" id="DropDownList1">
<asp:ListItem>01-january</asp:ListItem>
<asp:ListItem>02-feb</asp:ListItem>
<asp:ListItem>03-Mar</asp:ListItem>
<asp:ListItem>04-Apr</asp:ListItem>
<asp:ListItem>05-May</asp:ListItem>
<asp:ListItem>06-Jun</asp:ListItem>
</aspropDownList>
<br />
<input name="textfield23" type="text" id="textfield23" size="4" maxlength="8" class="inp" style="width: 101px; " /> </div>
<br /><br />
<div>Billing Address option
<input align="top" name="Radio4" type="radio" value="V1" id="decline1"
onClick="document.getElementById('dropdown3').styl e.display = 'none',
document.getElementById('accept1').checked = 0" />
Bill to Contact
Address

<input align="top" name="Radio5" type="radio" value="V1" id="accept1"
onClick="document.getElementById('dropdown3').styl e.display = 'block',
document.getElementById('decline1').checked = 0" checked="checked"/> Bill to a Different Address
</div>
</div>

im attaching the screeen shot.plz help.