Flex - Clearing DateField value on tab change in TabNavigator - actionscript-3

Question

I have the following tab navigator, which has a Project tab, containing a Combobox next to Release label as follows(AdditionalDetails.mxml):
Same tab navigator is having a Gate2 tab, which contains a DateField next to the label CERT load date, which can be seen below(Gate2.mxml):
Now, when I select Release as TBD on Project tab, an alert box appears as follows:
On clicking YES, I want to clear the DateField on Gate2 tab. How can I do so?
Code for Combobox(AdditionalDetails.mxml):
<mx:ComboBox id="General_Release_Dates"
selectedItem="{modelProxy.General_Release_Dates}"
valueCommit="{model.General_Release_Dates = event.currentTarget.selectedItem;updateReleaseDate(event)}"
change="{model.General_Release_Dates = event.currentTarget.selectedItem;updateReleaseDate(event)}" close="closeHandler(event);" includeInLayout="true" visible="true">
</mx:ComboBox
Code for handling YES click on Alert box:
private function alertClickHandler(evt:CloseEvent):void {
if (evt.detail == Alert.YES) { //Code to clear DateField}
DateField code on Gate2 tab(Gate2.mxml):
DateField code:<mx:DateField id="G2_CRTLoadDate" width="150" selectedDate="{modelProxy.G2_CRTLoadDate}" change="{modelProxy.G2_CRTLoadDate = event.currentTarget.selectedDate;changeManagerStatus()}"/>

Answer 1

Updated: Aug 31 23:27(JST)
If you're using singleton
Flex - Problems in accessing static variable on another mxml page
1) Create variable at your MySingleton class like below.
private var _gate2:Object;
public function set gate2(value:Object):void
{
_gate2 = value;
}
public function get gate2():Object
{
return _gate2;
}
2) Gate2.mxml (write at creationComplete event)
singleton.gate2 = this;
3) Control Gate2 from external class.
private function alertClickHandler(evt:CloseEvent):void {
if (evt.detail == Alert.YES) {
//Code to clear DateField
singleton.gate2.G2_CRTLoadDate.selectedDate = null;
}
}