All server controls must appear within a <form> tag, and the <form> tag must contain the runat="server" attribute. The runat="server" attribute indicates that the form should be processed on the server. It also indicates that the enclosed controls can be accessed by server scripts:
<form runat="server">
...HTML + server controls
</form>
Note: The form is always submitted to the page itself. If you specify an action attribute, it is ignored. If you omit the method attribute, it will be set to method="post" by default. Also, if you do not specify the name and id attributes, they are automatically assigned by ASP.NET.
Note: An .aspx page can only contain ONE <form runat="server"> control!
If you select view source in an .aspx page containing a form with no name, method, action, or id attribute specified, you will see that ASP.NET has added these attributes to the form. It looks something like this:
<form name="_ctl0" method="post" action="page.aspx" id="_ctl0">
...some code
</form>
source w3schools.com
<form runat="server">
...HTML + server controls
</form>
Note: The form is always submitted to the page itself. If you specify an action attribute, it is ignored. If you omit the method attribute, it will be set to method="post" by default. Also, if you do not specify the name and id attributes, they are automatically assigned by ASP.NET.
Note: An .aspx page can only contain ONE <form runat="server"> control!
If you select view source in an .aspx page containing a form with no name, method, action, or id attribute specified, you will see that ASP.NET has added these attributes to the form. It looks something like this:
<form name="_ctl0" method="post" action="page.aspx" id="_ctl0">
...some code
</form>
source w3schools.com
