onDragIn

fires when an item is dragged to a potential target (the event can be blocked)

void onDragIn(string|number dId,string|number tId,object sObj,object tObj);

dId	string\|number	the id of the dragged item
tId	string\|number	the id of the potential drop landing
sObj	object	a grid object
tObj	object	the target grid object

Available only in PRO Edition

mygrid.attachEvent("onDragIn", function(dId,tId,sObj,tObj){
    //your code here
});