为啥报错啊？

#include<bits/stdc++.h>
using namespace std;
void MainWindow::on_pushButton_clicked(){
	int flag=ui->lineEdit->text().toInt();
	if(falg==1){
		ui->label_4->setStylesheet("color:green;");
		ui->label_4->setText("green");
		ui->label_5->setText("empty parking space");
	}else{
		ui->label_4->setStyleSheet("color:red;");
		ui->label_4->setText("red");
		ui->label_5->setText("else empty parking space");
	}
}
int main(){
	
	return 0;
}