ÿþf u n c t i o n   i s N u m ( s t r )  
 {  
         f o r   ( v a r   i   =   0 ;   i   <   s t r . l e n g t h ;   i + + )   {  
             v a r   c h   =   s t r . s u b s t r i n g ( i ,   i   +   1 ) ;  
             i f ( ! ( ( c h   > =   " 0 "   & &   c h   < =   " 9 " )   | |   c h   = =   " . " ) )   {  
                 r e t u r n   f a l s e ;  
             }  
         }  
         r e t u r n   t r u e ;  
 }  
  
 f u n c t i o n   i s E m p t y ( s t r )  
 {  
         i f ( s t r . v a l u e . l e n g t h = = 0 )  
         {  
                 r e t u r n   f a l s e ;  
         }  
         r e t u r n   t r u e ;  
 }  
  
 f u n c t i o n   c h e c k _ m o b i l e ( s t r )  
 {  
 	 i f ( ! i s N u m ( s t r . v a l u e ) )  
 	 {  
 	 	 r e t u r n   f a l s e ;  
 	 }  
 	 v a r   m o b i l n u m b e r = s t r . v a l u e ;  
 	 v a r   s n u m b e r = m o b i l n u m b e r . s u b s t r ( 0 , 3 ) ;  
  
 	 i f   ( m o b i l n u m b e r . l e n g t h   ! =   1 1 )  
 	 {  
 	 	 r e t u r n   f a l s e ;  
 	 }  
 	 i f   ( ( s n u m b e r   ! = 1 3 5 ) & & ( s n u m b e r   ! = 1 3 6 ) & & ( s n u m b e r   ! = 1 3 7 ) & & ( s n u m b e r   ! = 1 3 8 ) & & ( s n u m b e r   ! = 1 3 9 ) )  
 	 {  
                 	 r e t u r n   f a l s e ;  
 	 }  
 	 r e t u r n   t r u e ;  
 } 
