SO - 29113698

HTML

<iframe name="hidden_iframe" id="hidden_iframe" style="display:none;" onload="if(submitted) {breakRedirect();}"></iframe>
<form action="https://docs.google.com/forms/d/1SueoRbKQ4LVp-S5jHyjper-ZVH1W3YgnA1ySoH9nC-k/formResponse" method="POST" id="mainform" target="hidden_iframe" onsubmit="submitted=true;">
    <div id="username">Username:
        <input type="text" name="entry.470211283" id="entry_470211283" dir="auto" aria-label="Username " aria-required="true" required="" title="Username" value="testname" tabindex="1" class="useLocal useLocalInput">
    </div>
    <div id="nameselections">
        <table id="maintable">
            <tr>
                <td>Name 1
                    <br>
                    <select name="entry.1382992313" id="entry_163533678" aria-label="1st" aria-required="true" required="" title="1" tabindex="2" class="useLocal useLocalSelect">
                        <option value="">-</option>
                        <option value="test1" selected="selected">test1</option>
                        <option value="test2">test2</option>
                        <option value="test3">test3</option>
                        <option value="test4">test4</option>
                        <option value="test5">test5</option>
                        <option value="test6">test6</option>
                        <option value="test7">test7</option>
                        <option value="test8">test8</option>
                        <option value="test9">test9</option>
                        <option value="test10">test10</option>
                    </select>
                </td>
                <td>Name 2
                    <br>
                    <select name="entry.574800946" id="entry_574800946" aria-label="2nd" aria-required="true" required="" title="2" tabindex="3" class="useLocal useLocalSelect">
                        <option value="">-</option>
                        <option value="test1">test1</option>
                        <option...

CSS

.duplicate {
    background-color: #ff9696;
}

JavaScript

function breakRedirect() {

		var month = new Array();
			month[0] = "01"; month[1] = "02"; month[2] = "03"; month[3] = "04"; month[4] = "05"; month[5] = "06"; month[6] = "07"; month[7] = "08"; month[8] = "09"; month[9] = "10"; month[10] = "11"; month[11] = "12";
		var collection = new Date().getDate() + "/" + month[new Date().getMonth()] + "/" + new Date().getFullYear() + " "+ new Date().getHours() + ":" + new Date().getMinutes() + ":" + new Date().getSeconds();
			
		var $inputs = $("input")
		$inputs.each(function () {
			var value = this.value;
			if (value != "Submit Selections" && value != "Clear Selections") {
				collection += "\t" + value
			};
		});
		
		var $selects = $("select")
		$selects.each(function () {
			var value = this.value;
			collection += "\t" + value
		});
		
		console.log(collection);
	
        $('#container').replaceWith('<div id="complete">Completed</div>');
    };

// Check for duplicates
function checkSelect() {
    var $selects = $("select").removeClass('duplicate');
    $selects.each(function () {
        var value = this.value;
        $selects.not(this).has('option[value="' + this.value + '"]:selected').addClass('duplicate');
    })
    var valid = !$selects.hasClass('duplicate');
    if (!valid) {
        var $div2 = $("#error").stop(true, true);
        if ($div2.is(":hidden")) {
            $div2.show("slow");
            setTimeout(function () {
                $div2.hide("slow");
            }, 10000);
        }
    }
    return valid;
};

$(function () {
    $('#mainform').submit(function () {
        // it's not doing anything
        //checkDropdowns()
        submitted = checkSelect();
        return submitted;
        //return true; // return false to cancel form action
    });
    $("select").on("change", function () {
        $(this).removeClass("duplicate");
    });
});