[Remove touchstart event from menu div]

Hello, I have a navigation bar which opens up a submenu with a mouseover event on pc and with a touch for ios. For ios devices the following code is utilized to close the menu on a touch event to the document.

<script>
document.onclick = mclose(); 
window.addEventListener('load', function (){ // on page load
    document.body.addEventListener('touchstart', function(e){
		if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
		    }, false)
 
}, false)
</script>

My question is - how can I remove the above EventListener from the div displayed as the submenu so that touching within that div does not close it and the links are functional? I am guessing there is a method using preventdefault that may be applied but I am uncertain.