function TreeAction(tree_btn)
{
	 var group_name = tree_btn.id.substr(0, tree_btn.id.length - 4);
	 
	 var section = document.getElementById(group_name + '_rows');
	 
	 if (tree_btn.innerHTML == '+')
	 {
		 tree_btn.innerHTML = '-';
		 
		section.style.visibility = 'visible'; 
	 } else {
		 tree_btn.innerHTML = '+';
		 
		 section.style.visibility = 'collapse';
	 }
}