I am working on one erp project. At this site, i have one one link, when i click on that link then it opens category tree page and please wait runs then i select item from tree and it fill all items in dropdownlist. again i click on link and opens category tree page but now it takes very much time in loading and after selection when it loads data in dropdownlist then also, it takes very much time. I am unknown from this issue, what is this and why occured? Please help me to solve this problem.