question on unique identifier

Hello, I was ask to use the data type unique identifer for the ID section of my my SQL, what i want to ask is whether the column with that data type will generate automatically the unique value whenever the user enters a data into the database. because that is what i want and I am unsure how to make the unique identifer becomes like auto numbering? This is my code for inserting data into the sql database:
<tr> <td class="td1"><div align="left"><span>Name</span></div></td> <td class="td1"><div align="left"><span> <asp:textbox id="first" Font-Names="Verdana" Font-Size="11px" runat="server" /> <asp:RequiredFieldValidator ID="start" runat="server" ControlToValidate="first" CssClass="text1" Display="Dynamic" ErrorMessage="* Required" ValidationGroup="error" /> </span></div></td> </tr> p ...