No one answered this question one morning. I'm so sad. change the title and continue to solve the problem.

One morning, no one answered the question. I changed the title and continued. I want to call a linkage category in Zhimeng member registration. how can I call it? & nbsp; for example, what I want to call in it is & nbsp; jiangbei district-Second Experimental Primary School-Third Experimental Primary School, js chant, the name of each form is written to the array, maintain an array record the number of items selected in each drop-down list currently, I have selected a form for each order. in the morning, no one answered the question. I'm so sad. change the title and continue.
How can I call a linkage category in Zhimeng member registration?

For example, what I want to call inside is
Jiangbei district
-- Second lab Primary School
-- Third lab Primary School

------ Solution --------------------
Js, the name of each form is written to the array. maintain an array record. the number of items selected in each drop-down list is selected currently. there is a selection event for each form, when this happens, the dom operation of the associated drop-down list will clear all options and add the options in the array again.