不正确的编译 warning

[neeme]

QHBoxLayout  *lay;

for(uint i=0;  i<16;  i++)
{
    if(i%4 == 0)
    {
        lay = new QHBoxLayout;
    }
    lay->addWidget(new QLabel("***"));
}

/home/neeme/vivere/ocean/Mint/FFreqBus.cpp:25: warning: ‘lay’ may be used uninitialized in this function [-Wmaybe-uninitialized]
lay->addWidget(f_cur_hz[i]);

请问怎样调整代码，才能令QT不再产生这样的提示呢？ 谢谢！