今天用vc++6.0写了段代码，总是提示错误 error C2143: syntax error : missing ')' before '{'检查了好几遍

Question

代码如下：还望高手帮忙找出错误，谢谢！！
#include "stdio.h"
#include "ctype.h"
main(){
char a[100];int i=0;
printf("please input the sentence:");
scanf("%s",a);
while(a[i]!='\0'){
if(isalpha(a[i]) {
if('a'<=tolower(a[i])&&tolower(a[i])<'x') a[i]=a[i]+3;
else a[i]=a[i]-29;}
}
printf("%s",a);
}

Answer 1

楼上正解
多报错了
syntax error : missing ')' before '{'
语法错误：在{前缺少）

Answer 2

#include "stdio.h"
#include "ctype.h"
main(){
char a[100];int i=0;
printf("please input the sentence:");
scanf("%s",a);
while(a[i]!='\0'){
if(isalpha(a[i])) {
if('a'<=tolower(a[i])&&tolower(a[i])<'x') a[i]=a[i]+3;
else a[i]=a[i]-29;}
}
printf("%s",a);
}//你在第八行丢掉了“）”

Answer 3

if(isalpha(a[i]) ){
这里差个括号啊