help with Animation?

So i have made a function that will allow me to change the poses of a given weld or part by adjusting their cframes but how can i have it detect if it has been called while it is still running ? like for example if i made the right arm go up in 10 seconds total time waited 5 seconds then made it go down in how could i make the function detect that the first animation was not finished cancel it then execute the second animation?

here is the function

    local frames = 25

    local function newPose(joint, finishCFrame, length)
        coroutine.resume(coroutine.create(function()
            local totalDurration = length * frames      
            local i = 0

            while true do
                joint = joint:lerp(finishCFrame, i)
                wait(1 / frames)
                i = i + (1 / totalDurration)

                if i == totalDurration then break end
            end
        end))
    end