名和姓的调换，代码求修正

[WaterCham]

输入一英文名，名在前，姓在后，通过函数把姓放在前，名在后。初次写的，不会很会。求修正。
还有调试时: warning C4047: 'function' : 'const char *' differs in levels of indirection from 'const int '
: warning C4024: 'strcat' : different types for formal and actual parameter 2

#include <stdio.h>
#include <string.h>

void changename(char *Name,char *NewName)
{
char *p;
p = strchr(Name,' ');
p = "\0";
strcpy(NewName, p+1);
strcat(NewName,'.');
strcat(NewName,Name);
p = " ";
}
void Mean()
{
printf("1.Enter The Name!\n");
printf("2.End The system\n");
}

int chooser(int x)
{
char Name[100],NewName[100];
if(x = 2) return 0;
else if(x = 1)
{
gets(Name);
changename(Name,NewName);
puts(NewName);
printf("\n");
Mean();
printf("Choose to control!:");
scanf("%d",&x);
chooser(x);
}
else
{
printf("ERROR!!");
printf("Choose to control!:");
scanf("%d",&x);
chooser(x);
}
return 1;
}


void main(void)
{
int x;
Mean();
printf("Please Enter Number!:");
scanf("%d",&x);
chooser(x);
}

[赵4老师]

请判断每个函数的返回值。

[max_min_]

p = "\0";
//楼主，这句话的意思不是赋值操作，而是让P指针指向了"\0"这个字符串常量