char *string_link(char str1[],char str2[])
{
     short int sa=sizeof(str1),sb=sizeof(str2),i;
     char *p=sa+str1-1;
     for(i=0;i<=sb-1;i++)
        {
                         *p=str2[i];
                         p++;
         }
     p=str1;                    
     return p;
}