AMpscript (SFMC) giving error : An IF statement is not closed with the required ENDIF statement

Question

I am showing a description based on the value of points

%%[ var @firstname,@memberid , @points , @desc

Set @firstname = [FirstName]
Set @memberid = [MemberId]
Set @points = [Points]

%%[ If @points > 150 Then ]%%
Set @desc = 'you are a platinum customer'
%%[elseif @points > 100 ]%%
Set @desc = 'You are a gold customer'
%%[elseif @points > 50 ]%%
set @desc = 'You are a silver customer'
%%[elseif  ]%%
set @desc = 'You are an insider customer'
%%[ENDIF ]%%

]%%

Dear %%=v(@firstname)=%% , Your  Member ID : %%=v(@memberid)=%%  . Based upon your points %%=v(@desc)=%%

I am getting an error: An IF/ELSEIF statement is invalid. No terminating THEN for the statement is found. Please Help !

Answer 1

Once you open a AMPscript block with %%[ you shouldn't have another open block till you close it, so your AMPscript should be something more like

%%[ var @firstname,@memberid , @points , @desc

Set @firstname = [FirstName]
Set @memberid = [MemberId]
Set @points = [Points]

If @points > 150 Then 
Set @desc = 'you are a platinum customer'
elseif @points > 100 THEN
Set @desc = 'You are a gold customer'
elseif @points > 50 THEN
set @desc = 'You are a silver customer'
else  
set @desc = 'You are an insider customer'
ENDIF ]%%