TypeError: stepUp called on an object that does not implement interface HTMLInputElement

If search_term is an input field you might want to get its value.

var search_term = $(this).parents('.sub-middle-column').find('.search_horse').val();

Right now you are referencing a jQuery Object containing a HTMLDom-Element but I think what you want is the string inside the search input element.

TypeError: stepUp called on an object that does not implement interface HTMLInputElement comes when you forget # sign for(id) and . sign for class. when we can get value directly without . or # sign.

Wrong method: - var email = $('PHMC_email').val();

Correct Method:

-var email = $('#PHMC_email').val(); Or var email = $('.PHMC_email').val();