Declare @Id Int                               
Select @Id = Id From sysobjects Where Name = 'Label_Print'
if  Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L1')
  Alter table Label_Print alter column L1 nvarchar(200) null
  
                           
Select @Id = Id From sysobjects Where Name = 'Label_Print'
if  Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L2')
  Alter table Label_Print alter column L2 nvarchar(200) null
  
  
                             
Select @Id = Id From sysobjects Where Name = 'Label_Print'
if  Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L3')
  Alter table Label_Print alter column L3 nvarchar(200) null
      
 
                              
Select @Id = Id From sysobjects Where Name = 'Label_Print'
if  Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L4')
  Alter table Label_Print alter column L4 nvarchar(200) null
    
                            
Select @Id = Id From sysobjects Where Name = 'Label_Print'
if  Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L5')
  Alter table Label_Print alter column L5 nvarchar(200) null 


Select @Id = Id From sysobjects Where Name = 'Label_print'
if  not Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'L6')
 alter table Label_print add  L6  Nvarchar(200) Null