请问javascript如何进行加法运算呢？

[cheng17]

function totala()
{var hire2,manager2,eletricity2,water2,corntry2,place2,total2;
hire2=document.all.form1.hire.value;
manager2=document.all.form1.manager.value;
eletricity2=document.all.eletricity.value;
water2=document.all.water.value;
corntry2=document.all.corntry.value;
place2=document.all.place.value;

document.all.total.value=hire2+manager2;

[cheng17]

谢谢楼上各位！

[KimSoft]

document.all.total.value=parseFloat(hire2)+parseFloat(manager2);

//or parseInt

[笨笨兔兔兔兔兔]

parseInt

[jspadmin]

先转换成数字型，再运算