<input type="text" onkeypress="checknum()" onkeyup="cal(this)">
<input type="text" name="result">
<script language="javascript">
function checknum()
{
if ((event.keyCode < 45 || event.keyCode > 57) && event.keyCode!=13)
event.returnValue = false;
}
function cal(obj)
{
if(obj.value=="")
return false;
num=parseInt(obj.value)
document.all.result.value=num*0.8
}
</script>
<input type="text" name="result">
<script language="javascript">
function checknum()
{
if ((event.keyCode < 45 || event.keyCode > 57) && event.keyCode!=13)
event.returnValue = false;
}
function cal(obj)
{
if(obj.value=="")
return false;
num=parseInt(obj.value)
document.all.result.value=num*0.8
}
</script>
function cal(obj)
{
if(obj.value=="")
return false;
num=parseInt(obj.value)
document.all.result.value=(num*0.8).toFixed(1);}
如果是含小数function cal(obj)
{
if(obj.value=="")
return false;
num=parseFloat(obj.value)
document.all.result.value=num*0.8;}
{
if(obj.value=="")
return false;
num=parseFloat(obj.value)
document.all.result.value=(num*0.8).toFixed(2);
}
if(obj.value=="")
{
document.all.result.value="";
return false;
}
改为
<input type="text" name="result">
<script language="javascript">
function checknum()
{
if ((event.keyCode < 45 || event.keyCode > 57) && event.keyCode!=13)
event.returnValue = false;
}function cal(obj)
{
num=parseFloat(obj.value)
if(isNaN(num))
{
obj.value=""
document.all.result.value=""
return false;
}
else
{
obj.value=num
document.all.result.value=(num*0.8).toFixed(2);
}
}
</script>