How we can implement the Onclick functionality in titanium grid view item

Hi.,

I have developed the gridview application using the widget (from this code)

https://github.com/pablorr18/TiDynamicGrid

i have modified the code as per my client requirements. Now if i like to click the view cart button on the list item it will alert the message like "Am clicked". But i tried in various ways.but i can't find the solutions. Can anyone please explain me how we are write the code for this.

I have follows below code in my application:

  var items = [];
   var showGridItemInfo = function(e){
alert("Onclick the row");

}; var delay = (OS_ANDROID) ? 1000:500;

    $.tdg.init({
columns:3,
space:5,
delayTime:delay,
gridBackgroundColor:'#e1e1e1',
itemBackgroundColor:'#fff',
itemBorderColor:'transparent',
itemBorderWidth:0,
itemBorderRadius:5,
onItemClick: showGridItemInfo

});

     function createSampleData(){
          var sendit = Ti.Network.createHTTPClient({ 
                 onerror: function(e){ 
                       Ti.API.debug(e.error); 
                       alert('There was an error during the connection'); 
                 }, 
              timeout:10000, 
          });           

          sendit.open('GET', url+'android_livedev/client/mallthai.php?action=listitems&categoryid='+subcategorylist_category_id+'&productmin=0&productmax=50');  

          sendit.send(); 
          sendit.onload = function(){ 
                var response = JSON.parse(this.responseText); 
                    if(response[0].success == 0){
                     alert("No Products Found");
         }
         else {
                     items = [];   
for (var x=0;x<response[0].data.length;x++){
var view = Alloy.createController('item_layout',{
        image:imageurl+response[0].data[x].thumb_image,
        product:response[0].data[x].product,
        productprice:"$"+" "+response[0].data[x].price,
        onItemClick: addcart,
    }).getView();
    var values = {
        product: response[0].data[x].product,
        image: response[0].data[x].thumb_image,
        productid : response[0].data[x].productid,
    };
    items.push({
        view: view,
        data: values
    });
};
$.tdg.addGridItems(items);
    reateSampleData();

    $.tdg.clearGrid();
      $.tdg.init({
    columns:nColumn,
    space:nSpace,
    delayTime:delay,
    gridBackgroundColor:'#e1e1e1',
    itemHeightDelta: 0,
    itemBackgroundColor:'#fff',
    itemBorderColor:'transparent',
    itemBorderWidth:0,
    itemBorderRadius:5,
    onItemClick: showGridItemInfo
});
     createSampleData();

});

        $.win.open();

The item_layout.xml code is looking like :

<Alloy> <View id="mainView"> <ImageView id="thumb"/> <Label id="product"></Label> <Label id="productprice"></Label> <Button id="addcart" onClick="additemtocart"/> </View>
</Alloy>