Toolbar issue in text field with numpad

I have textfield with numpad. I want to show done button on top of numpad and want to hide numpad when I click done button.

XML

<Alloy>
    <Window id="AddTransafer" title="" fullscreen="false" modal="true"  barImage="Images/IPhone-retina_Header01.png" backgroundImage="Images/IPhone-retina_02.png" backgroundRepeat="false" onClick="closeNumPad" 
        onFocus="loadDetails">
        <TitleControl>
            <Label id="titleControl" color="white">MAKE A TRANSFER</Label>
        </TitleControl> 
        <ScrollView contentWidth= "auto" contentHeight= "auto" showVerticalScrollIndicator= "true">
 
    <
 
            <TextField top="290" width="527px" height="73px" id="inputAmount" hintText="Enter Amount" keyboardType="Ti.UI.KEYBOARD_NUMBER_PAD" width="527px" height="73px" borderStyle="Titanium.UI.INPUT_BORDERSTYLE_NONE" backgroundColor="#ffffff" paddingLeft="5"/>
        </ScrollView> 
</Window>
</Alloy>

CS

function loadDetails(){
    initiateAmount();
    // rest of the logic .. 
 
}
function initiateAmount(){
    var doneButton = Titanium.UI.createButton({    
        title : 'Done',
        width : 67,
        height : 32
    });
 
    doneButton.addEventListener('click', function(e) { 
        $.inputAmount.blur(); 
    });
    $.inputAmount.keyboardToolbar = [doneButton];
    $.inputAmount.addEventListener('focus', function(e) {
        $.inputAmount.keyboardToolbar = [doneButton];
    });
}

The problem is that when I click first its appearing like this. When I double clicking its working fine. It has also issues when I press done and click on field again. I am attaching the screenshot for the reference.