EEPW论坛

PROCESS(CLK,DATA_F) IS
   BEGIN
 IF(CLK'EVENT AND CLK='1') THEN
  IF NC=4 THEN
   IF DATA_F(2)='1'THEN    --上锁控制信号有效 (0100)
      REG<=ACC;       --密码存储 
      QA<='1'; QB<='0'; 
   ELSIF DATA_F(0)='1'THEN --开锁控制信号有效 (0001)
    IF REG<=ACC THEN   --密码核对
     QA<='0'; QB<='1';
ELSE
 IF CNT="11"THEN 
   ALERT<='1';CNT<="00"; 
   ELSE 
   CNT<=CNT+1;QA<='1';QB<='0';ALERT<='0';
   END IF; 
    END IF; 
    ELSIF ACC<="1000100010001000"THEN   
          --设置"8888"为万用密码 
    QA<='0';QB<='1'; 
   END IF; 
  END IF; 
 END PROCESS;

程序出现以下问题error:line 7:assignment statement must have ':='or'<=',but found<identifier> REG instead.

error:line 10:assignment statement must have ':='or'<=',but found  IF instead.

不知道怎么改，求帮忙