Sequence Assurance in Remoting

Please see the following codes;
#include "NetServices.as"
#include "NetDebug.as"

NetServices.setDefaultGatewayURL("http://mail.microweb.com.hk/~admin/ecat2/ecatgateway.php");
var myServer = NetServices.createGatewayConnection();
var categoryMgr = myServer.getService("categoryctl", this);

_global.getName = "";
_global.getParentID = -1;
_global.getListByParent = new Array();

function getName_result(theResult)
{
_global.getName = theResult;
}

function getParentID_result(theResult)
{
_global.getParentID = theResult;
}

function getListByParent_result(theResult)
{
_global.getListByParent = new Array();
for (var idx in theResult)
{
_global.getListByParent.push(theResult[idx]);
}

myDate = new Date();
trace(myDate.getTime() + ":" + _global.getListByParent.length + "\n");
}

lblDebug.text = "Debug:";
// line 1
categoryMgr.getListByParent(-1);
myDate = new Date();
// line 2
trace(myDate.getTime() + ":" + _global.getListByParent.length + "\n");

// End of The Code

Output:
1060393964995:0

1060393965256:2


How can I ensure that line 2 will not run until the completion of line 1? or do we have any special algorithm to perform such task?