C++ Bank程序无法正常堆栈溢出

我试图用C++制作一个银行程序,在那里你可以查看钱包里的金额,以及你的银行账户中的存款和取款金额.当我尝试运行它时,它让我输入,但是当我输入任何内容时,它会Money in Wallet: 20一次又一次地重复,直到我得到堆栈溢出,我认为这有点讽刺,在一个名为Stack Overflow的网站上发布.

到目前为止这是我的代码:

#include 
using namespace std;

float money= 20.00;
float account=100.00;
float amount;
bool cmd;

void wallet()
{
    cout<<"Money in Wallet: "<>amount;
    if (money>=amount)
    {
        account = account+amount;
        money = money-amount;
    }
    else
    {
        cout<<"You don't have enough money!\n";
    }
}


void withdraw()
{
    cout<<"How much do you want to withdraw?: ";
    cin>>amount;
    if(account>=amount)
    {
        money = money+amount;
        account = account-amount;
    }
    else
    {
        cout<<"There isn't enough money in your bank account!\n";
    }
}


void prompt()
{
    cmd="null";
    cout<<">";
    cin>>cmd;
    if (cmd="wallet")
    {
        wallet();
        cmd="null";
        prompt();
    }
    else{
        cout<<"Unknown Command.";
        cmd="null";
        prompt();
    }
    if (cmd="bank")
    {
        bank();
    }
    else{cout<<"Unknown Command.";}
    if (cmd="deposit")
    {
        deposit();
    }
    else{cout<<"Unknown Command.";}
    if (cmd="withdraw")
    {
        withdraw();
    }
    else{cout<<"Unknown Command.";}
}


int main()
{
    prompt();
}

请帮忙!