To disable a linkbutton, you can call 'disable' method or set the 'disabled' to true.
<script type="text/javascript">
$(function(){
$('#dlg').dialog({
buttons: [{
id:'mybutton',
text:'Ok',
iconCls:'icon-ok',
handler:function(){
alert('ok');
}
},{
text:'Cancel',
disabled:true,
handler:function(){
alert('cancel');;
}
}]
});
$('#mybutton').linkbutton('disable');
})
</script>