$(document).ready( function() { var val = $("select[name=id_country]").val(); if (val!=181) $("tr#tr_id_russianregion").hide(); $("select[name=id_country]").change( function() { if (this.value==181) $("tr#tr_id_russianregion").show(); else $("tr#tr_id_russianregion").hide(); } ); } );