dragCallback Buggy / not Functioning

 
global proc string[] MyDropCallBack(string $dragControl, string $dropControl, string $msgs[], int $x, int $y, int $type)
 
{ 
 
print "hellooOOo Why This Print Doesn't Working ?.why no triggering ?";
string $myArray[]={ "an empty array" };
return $myArray;
}
window;
paneLayout;
 
textScrollList -numberOfRows 8 -allowMultiSelection true
-dropCallback MyDropCallBack
-append "one" -append "two" -append "three"
-append "four" -append "five" -append "six"
-append "seven" -append "eight" -append "nine"
-append "ten" -append "eleven" -append "twelve"
-append "thirteen" -append "fourteen" -append "fifteen"
showWindow;
 

global proc TestDropCB( string $dragControl, string $dropControl, string $msg[], int $x, int $y, int $type)
	{
	print "Testing drop callback\n";
	}

global proc string[] TestDragCB(string $dragControl, int $x, int $y, int $mods)
	{
	print "Testing drag callback\n";
	return{" an empty array "};
	}

window;
paneLayout; 
textScrollList
	-numberOfRows 8
	-allowMultiSelection true
	-dragCallback TestDragCB
	-dropCallback TestDropCB
	-append "one" -append "two" -append "three"
	-append "four" -append "five" -append "six"
	-append "seven" -append "eight" -append "nine"
	-append "ten" -append "eleven" -append "twelve"
	-append "thirteen" -append "fourteen" -append "fifteen";
showWindow;