type mismatch with asp function

I'm getting a type mismatch error with this scrtipt.
I added the third line,
max_length=cint(max_length)
to make sure that the max_length variable would be numerical so that it would work as an argument in the left(function).I got the same error message with and without this line.

What did I do wrong here?

function strEncode(input_str,max_length)
input_str=trim(input_str)
max_length=cint(max_length)
input_str=left(input_str,max_length)
input_str=replace(input_str,",",",")
input_str=replace(input_str,"""",""")
input_str=replace(input_str,"'","'")
strEncode=input_str
end function
sqlstr="SELECT * FROM institutions;"
rs1.Open sqlstr,con,3,3
rs1.AddNew
rs1.fields("date_entered")=date()
input_str=request.form("text_institution_name")
/error here/ input_str=str_Encode(input_str,10) rs1.fields("name")=input_str
rs1.update
rs1.close