Redirecting to a thank you page Dreamweaver Form Using asp w/godaddy server

I have a simple contact form and I want to redirect to a thank you page after the send (submit) button is clicked. I thought I could just fill in the url after onClick="" but it is not working, it is going to my home page. I am using godaddy for hosting and they are using asp to send the form, but I have no control over this end of it. I just turn it “on or off” and direct my form to use it, so maybe that is where the issue is? Anyway here is the form:

<form action="gdform.asp" method="post"> 
              <table width="80%" border="0" align="center"> 
                <tr> 
                  <td width="14%"><p align="left"><font color="#000000">First Name:</font></p></td> 
                  <td width="86%"> <input name="FirstName" type="text" id="nametext1" size="50" maxlength="50"></td> 
                </tr> 
                <tr> 
                  <td><p align="left"><font color="#000000">Last Name:</font></p></td> 
                  <td><input name="LastName" type="text" id="LastName" size="50" maxlength="50"></td> 
                </tr> 
                <tr> 
                  <td><p align="left"><font color="#000000">Email:</font></p></td> 
                  <td><input name="email" type="text" id="email" size="50" maxlength="50"></td> 
                </tr> 
                <tr> 
                  <td valign="top"> <p align="left"><font color="#000000">Comments:</font></p></td> 
                  <td><textarea name="comments" cols="38" rows="10"></textarea></td> 
                </tr> 
                <tr> 
                  <td>&nbsp;</td> 
                  <td> <div align="left"> 
                      [COLOR="Red"]<input type="submit" name="submit" value="Send" onClick="http://www.studio718hair.com/thankyou.html" size="25"> [/COLOR]                      <input type="reset" name="reset" value="Cancel" size="50"> 
                    </div></td> 
                </tr> 
              </table>
          </form>