I'm trying to basically take 2 parts of a search URL and add the option selections in the middle to create an overall working search URL.
For some reason the way I'm trying to target the options selected values is not working, and causing the whole href.location to not work at all.

Can anyone tell me what's wrong with my onClick in the Submit button?

Code:
<form name="redlinesearch">
<select name="redline_inches" id="redline_inches">
<option value="14x+">14"</option>
<option value="15x+">15"</option>
<option value="16x+">16"</option>
<option value="17x+">17"</option>
<option value="18x+">18"</option>
<option value="20x+">20"</option>
<option value="22x+">22"</option>
<option value="24x+">24"</option>
<option value="26x+">26"</option>
<option value="28x+">28"</option>
<option value="30x+">30"</option>
</select>

<select name="redline_boltpattern" id="redline_boltpattern">
<option value="4-100">4-100</option>
<option value="4-108">4-108</option>
<option value="4-114.3">4-114.3</option>
<option value="5-100">5-100</option>
<option value="5-108">5-108</option>
<option value="5-110">5-110</option>
<option value="5-112">5-112</option>
<option value="5-114.3">5-114.3</option>
<option value="5-115">5-115</option>
<option value="5-120">5-120</option>
<option value="5-127">5-127</option>
<option value="5-135">5-135</option>
<option value="5-139.7">5-139.7</option>
<option value="5-150">5-150</option>
<option value="6-127">6-127</option>
<option value="6-135">6-135</option>
<option value="6-139.7">6-139.7</option>
<option value="8-165">8-165</option>
<option value="8-170">8-170</option>
</select>


<input type="submit" value="Search Now" onClick="location.href='http://www.redlinewheel.com/index.php?search_performed=Y&match=all&q='+redline_inches.options[selectedIndex].value+'+'+redline_boltpattern.options[selectedIndex].value+'+'&pname=N&pfull=Y&cid=0&pcode=&price_from=&price_to=&weight_from=&weight_to=&dispatch[products.search]=Search'" />

</form>