<img src="http://javascript.ru/forum/images/smilies/sad.gif" class="onclick" onclick="inp.value = ~~inp.value <= 1 ? 1 : ~~inp.value - 1"/>
<input tape="text" id="inp" value="1" class="input">
<img src="http://javascript.ru/forum/images/smilies/smile.gif" class="onclick" onclick="inp.value = ~~inp.value >= 5 ? 5 : ~~inp.value + 1"/>