Use the layout component of easyui, as shown in Figure 1 below. After an iframe with a height of 100% is embedded in the center, a vertical scroll bar will appear in the div containing this iframe.
Figure 1
Without easyui, after directly nesting the iframe for testing, I found that after setting
body{margin:0;padding:0;}
Did it myself
http://stackoverflow.com/questions/9129182/iframe-100-height-causes-vertical-scrollbar