Simple Function Problem, please help

[ShadowWarrior17]

row6="|   |   |   |   |   |   |   |"
row5="|   |   |   |   |   |   |   |"
row4="|   |   |   |   |   |   |   |"
row3="|   |   |   |   |   |   |   |"
row2="|   |   |   |   |   |   |   |"
row1="|   |   |   |   |   |   |   |"
dboard=[row6,row5,row4,row3,row2,row1]
l="-----------------------------"


def drawboard():
    print("| 1 | 2 | 3 | 4 | 5 | 6 | 7 |")
    print(l)
    for x in dboard:
        print(x)
        print(l)

def columncheck(c):
    x=5
    pos=False
    while pos != True:
        if dboard[x][(4*c)-1]== " ":
            pos=True
        elif dboard[x][(4*c)-1] != " ":
            x-=1
    return x

That is my part of my code. It will be a connect 4 game, the function should check if the most bottom row full. Hopefully that adds some context. The problem is that no matter what, the function columncheck©, will ALWAYS return five, whether the position is taken or not.