I'm pretty sure that there are multiple form forms in the ASP that you used to do, in the background Classification Admin page, add and modify on the same page, so you need to use two form forms for submitting server code processing.
After testing, ASP.net can also have multiple form forms on a page, such as the following code:
<form id= "Form1" ></form><form id= "Form2" ></form><form id= "FORM3" ></form>
However, form forms cannot be nested, for example, the following code is incorrect:
<form id= "Form1" ><form id= "Form2" ></form></form>
It is also important to note that in asp.net, when there are multiple form forms in a page, only one form is allowed to have runat= "server" attributes, otherwise an exception is generated. This is some of the asp.net programming of children's shoes often make mistakes!
In ASP.net's programming mode, there are few situations where two or more form forms appear on a page. The function submitted to the server code can be done through a outermost form form, no need to do so much, this is asp.net and ASP differences!
I hope you can remember this!