Case statement script error

[4tkaruna]

i have the following code but couldn't figure out why the error is generated.
Trying to label the value based on the input selection.
Any help will be appreciated

#Moving Average of 8/50/200 EMA/SMA (6 different combination)
#AverageType.SIMPLE = 0 averageType.EXPONENTIAL = 1 AverageType.WEIGHTED = 2 AverageType.WILDERSAverage = 3 AverageType.HULL = 4

input Period = AggregationPeriod.DAY;
input AvgType = AverageType.EXPONENTIAL;
### input Tag = {default SMA , EMA};
#input Length = {default 8, 50, 200}; #Error
input Length = {default "8", "50", "200"}; # NO Error. this integer or text?
input priceclose = close;

def tag;

#Both block of code generate error.
if AvgType = 0 {
tag = "SMA";
} else if AvgType = 1{
tag = "EMA";
}

switch AvgType{
case 0:
tag = "SMA";
case 1:
tag = "EMA";
case 2:
tag = "WGHT";
}

def AVG = MovingAverage(AvgType, close(period = Period), Length); #Error
AddLabel(yes, Length + " " + tag + ": " + Round(AVG, 2), if close > AVG then Color.GREEN else Color.RED);
#