jQuery Grid Plugin - jqGrid

Hello,

I have a small problem that maybe you guys can help me. I want to add a button to the grid that changes value depending on the line ie:

onSelectRow: function(id)

{

jQuery('#organismos').jqGrid('navButtonAdd', '#pager1',{caption: "", buttonicon: "ui-icon-image", title: "Árvore dos objetivos Estratégicos e Operacionais",onClickButton: function() {window.open('Hierarquia/tree_objetivos.php?idorg=' + id, '_blank');

}    

Problem is that it will keep adding buttons. And what I wanted was for him to change value so each time you select a row. Someone can help me?