ajax multiple,jquery - Ajax multiple array not working - Stack Overflow

When I select values from two different select I get an error tmp is null

Men Foreigner

Women Foreigner

Black

Blond

jQuery part

$("select.select").change( function() {

var Thedata = $("#filterform").serialize();

console.log(Thedata);

$.ajax({

data: Thedata,

type: 'POST',

url: 'autocomplete.php?cat=filtermodelscall',

})

.done(function( html ) {

$("tbody").html( html );

});

});

Log shows Thedata values which is category%5B%5D=10&hair%5B%5D=Black

I have no idea where come from this error. Also, when I select values from a single select, it is working.

Thank you for your help