I need to validate a column when another has a value X

I Have :

$col = array();
$col["title"] = "Asistencia Len";
$col["name"] = "asislen";
$col["edittype"] ="select";
$col["editoptions"] =array("value"=>'P:P;N:N;A:A');
$col["width"] = "2";
$col["editable"] = true;
$col["align"] = "center";
$cols[] = $col;

$col = array();
$col["title"] = "No Pertenece";
$col["name"] = "noPertenece";
$col["edittype"] ="select";
$col["editoptions"] =array("value"=>'Si:Si;No:No');
$col["width"] = "2";
$col["editable"] = true;
$col["align"] = "center";
$cols[] = $col;

I Need:
If noPertenece == 'Si' and asislen =='P'
Then Alert
Else
Nothing

I can do this?