$(document).on("ready", function() {
$('input[advancedtype="searchselect"]').after('<div class="drophelp">TEST</div>');
}
$( "#content" ).load( "form.html"); }
<input type="text" advancedtype="searchselect">
$(document).on('ready', function() {
$('#content').load('form.html', function() {
$('input[advancedtype="searchselect"]').after('<div class="drophelp">TEST</div>');
});
});