如何累加网页中两个文本框的值?
有三个文本框
<input type="text" name="txt_amount1" size="60" onkeyup="javascript:caculate();">
<input type="text" name="txt_amount2" size="60" onkeyup="javascript:caculate();">
<input type="text" name="txt_total_amount" size="60" >
function caculate()
{
var amount1,amount2;
amount1=form1.txt_amount1.value;
amount2=form1.txt_amount2.value;
form1.txt_total_amount.value=txt_amount1和txt_amount2值的总和
“=后的表达式怎么写”
}
谢谢回复