Questions about frameset loading order_html/css_WEB-ITnose

The code is as follows:

The interface is divided into two columns. The left is the tree structure menu, and the right is the main functional area. In the right interface, there is a ToolBar, which is The corresponding operation permissions must be assigned according to the running permissions on the left, that is, you should run "fLeft" first, go to the corresponding permission parameters, and then run fRight. However, debugging found that the loading order of the browser is not necessarily certain, and sometimes Load fLeft first, sometimes load fRight first. Masters, please tell me, is there any way to set it to load from fLeft first? .

Reply to discussion (solution)

Set the right src to empty
After loading js on the left, set the right src

Set the right src to empty
After loading the js on the left, set the right src

How to write the js to set the right src? ? There is no fRight item in this.parent.item. Did I write it wrong? ?

Write in Page_Load of LeftTree.aspx:
Response.Write("