html control vs asp control in asp.net webform

Question

My question is that using only html controls instead of asp control in asp.net website is better idea or not..? i just want to use html control because in my form there is a dropdown list in which when i select country it automatically detect the state of that country and display in state dropdown without refreshing the webpage.

so can i apply this ajax method to asp dropdown or not..?

 

acually one of my friend told me that by using html control, your site will be light weighted thats why i am using html tags(input type="text">) in place of  asp controlo (ex;-<asp:textbox> )