sets a label for the left list
webix.ui({
view:"dbllist",
value:"1,2",
labelLeft:"All groups",
labelRight:"Selected",
data:[
{id:"1", value:"Contacts"},
{id:"2", value:"Products"},
{id:"3", value:"Reports"},
{id:"4", value:"Customers"},
{id:"5", value:"Deals"}
]
});