From MSDN:
When CommandType is set to Text, the .NET Framework Data Provider for ODBC does not support passing named parameters to an SQL statement or to a stored procedure called by an OdbcCommand. In either of these cases, use the question mark (?) placeholder. For example:
SELECT * FROM Customers WHERE CustomerID = ?
Rewrite your query to
OdbcConnection conn = new OdbcConnection(connString);
String query = "INSERT INTO customer (custId, custName, custPass, "+
"custEmail, custAddress, custAge) VALUES (" +
"?, ?, ?, ?, ?, ?)";
Order of Parameter counts!
EDIT: Parameter can be added this way:
OdbcCommand exe = new OdbcCommand(query, conn);
exe.Parameters.Add("ID", OdbcType.UniqueIdentifier).Value = id;
exe.Parameters.Add("Name", OdbcType.VarChar).Value = name;
exe.Parameters.Add("Pass", OdbcType.VarChar).Value = pass;
exe.Parameters.Add("Email", OdbcType.VarChar).Value = email;
exe.Parameters.Add("Address", OdbcType.VarChar).Value = address;
exe.Parameters.Add("Age", OdbcType.Int).Value = age;