Hi,

You need the CellWidget-module of gridx:

 {moduleClass:"gridx/modules/CellWidget"},

After that you need to define the Button in the column-JSON:

 {field:'colButtons', width:'80px', widgetsInCell: true, 
decorator: function(){return "<button data-dojo-type='dijit.form.Button' data-dojo-attach-point='btnDetails'></button>";}, 
setCellValue: function(gridData, storeData, cellWidget)
{
cellWidget.btnDetails.set('title', 'Details');
cellWidget.btnDetails.set('iconClass', 'detailsIcon');
cellWidget.btnDetails.set('showLabel', false); 
if(cellWidget.btnDetails._cnnt){cellWidget.btnDetails._cnnt.remove();} //remove all other callbacks
     cellWidget.btnDetails._cnnt = dojo.connect(cellWidget.btnDetails, 'onClick', function(e){alert(gridData);}); //create new onClick-Event
},
},