The error occurred maybe because you have record(s)that the Name field of theme are Null , add and null check to end of your query :
SELECT [employee ID], Password, Name FROM Employees WHERE Name = ' + name + ' AND Name IS Not Null';
Why you check the login this way ? you can easily do all login checks usign T-SQL query like :
form1.ADOQuery1.Active := False;
form1.ADOQuery1.SQL.Text := 'SELECT [employee ID], Password, Name FROM Employees WHERE Name = ' + name + ' AND Password = ' + Password + ' AND[employee ID] =' + ID;
form1.ADOQuery1.Active := True;
if (form1.ADOQuery1.RecordCount > 0) then
else