assigning mongoose result feild value to vriable in express

i am trying to assign value of a feild from momgoose to a variable which would be used as value to another feild in another schema which is as follows.

function getNextSequence() {
    var x = null
    relcounter.findOne({"name":"cabi"},'seq',  function (err, configs) {
    x=configs.seq
     console.log("##"+x)
     })
     console.log(x)

}

X is coming out to be null Also i need this value of x to add to another feild which is as follows

relconf.update( 
                   {name:"css"},
                    { $push: { relations: {id:getNextSequence(),name:req.body.name,divId:"name_div"} } }

Basically ineed the function getNextsequence to return the value of seq feild and assign to id feild can anyone suggest proper code and reason for null value for getNextSequence()

via Nitika Jain