first 1.16.9 code as below:
Code
<layer name="scrollarea" url="%SWFPATH%/plugins/scrollarea.swf"
alturl="%SWFPATH%/plugins/scrollarea.js" align="center"
width="350" height="350" direction="all" >
<layer name="map" align="center" enabled="true" capture="true"
scalechildren="True" children="True"
onhover="set(control.mousefovchange,0);set(events.onmousewheel,if(wheeldelta GT 0,if(layer[map].scale LT 1.1,add(layer[map].scale,0.1)),if(layer[map].scale GT 0.7,sub(layer[map].scale,0.1))));" onout="set(events.onmousewheel,NULL);set(control.mousefovchange,1);" >
BUT in 1.17 plugins maybe there is scrollarea.mwheel setting, then the child layer[map] can not get the right mousewheel behaviour ,can not get the right scale。