Create-toggle a modal.js

function toggleDetails (element, setOpen) {
	
	const attr = document.createAttribute('open')
			
	if (setOpen===undefined) {
		
		if (element.hasAttribute('open'))
			element.removeAttribute('open')
		else {
			element.setAttributeNode(attr, 'true')
		}
	}
	
	if (setOpen)
		element.setAttributeNode(attr, 'true')
	
	if (!setOpen)
		element.removeAttribute('open')
	
}
function setModalMenu (doOpen) {
	  		
	  		if(doOpen) {
		  		
			  	toggleDetails(leftNodes, true)
					document.body.style.overflowY='hidden'
			  	
					// Navigates through menu
					let i = 0
					let leftNodesArr = Array.from(leftNodes.children)
					let max = parseInt(leftNodesArr.length)-1
					document.addEventListener('keyup', function(e) {
						
						if (e.key === 'ArrowDown') 
							i = i==max ? 0 : i+1
						else if (e.key === 'ArrowUp')
							i = i==0 ? max : i-1
						leftNodesArr[i].focus()
						
					})
				}
		  	else if (!doOpen) {
				  toggleDetails(leftNodes, false)
				  document.body.style.overflowY='scroll'
		  	}
	  	}