var datagrid = $('#dataGridMaster');

var rowIndex =
$("#dataGridMaster").datagrid("getRowIndex",
$("#dataGridMaster").datagrid("getSelected"));

var field = 'CustomerID';

var row = datagrid.datagrid('getPanel').find('.datagrid-view1
.datagrid-body').find('tr[datagrid-row-index="' + rowIndex + '"]');

var value = row.find('td[field="' + field +
'"]>.datagrid-cell').html();

alert(value);