<script language="JavaScript"><!--
function mm()
{
with(document.hrong)
{
if (yyy.options[yyy.selectedIndex].text == '正常') {
if (!txt1.value || !txt2.value){
alert('有一项为空, 不予计算!');
return;
}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
else if (yyy.options[yyy.selectedIndex].text == '反常') {
txt3.value = 0;
}
}
}
//--></script>
function mm()
{
with(document.hrong)
{
if (yyy.options[yyy.selectedIndex].text == '正常') {
if (!txt1.value || !txt2.value){
alert('有一项为空, 不予计算!');
return;
}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
else if (yyy.options[yyy.selectedIndex].text == '反常') {
txt3.value = 0;
}
}
}
//--></script>
<head></head><body >
<form name=hrong>
<select name="yyy" id="yyy" >
<option selected >正常</option>
<option value="0">反常</option>
</select>
</font>
<input name=txt1 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt2 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt3 onkeydown="if(event.keyCode==13)event.keyCode=9" onfocus="mm()"><br>
</form>
<SCRIPT LANGUAGE="JavaScript"><!--
function mm()
{
with(document.hrong)
{
if(document.getElementById("yyy").value==0){
alert("反常");
txt3.value=0;}
else{
if(!txt1.value || !txt2.value){alert('有一项为空, 不予计算!'); return;}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
}
}
//--></SCRIPT>
</body>
</html>
<head></head><body >
<form name=hrong>
<select name="yyy" id="yyy" >
<option selected >正常</option>
<option value="0">反常</option>
</select>
</font>
<input name=txt1 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt2 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt3 onkeydown="if(event.keyCode==13)event.keyCode=9" onfocus="mm()"><br>
</form>
<SCRIPT LANGUAGE="JavaScript"><!--
function mm()
{
if(document.getElementById("yyy").value==0){
alert("反常");
txt3.value=0;}
else{
if(!txt1.value || !txt2.value){alert('有一项为空, 不予计算!'); return;}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
}
//--></SCRIPT>
</body>
</html>再试,我在IE下通过测试
<select name="yyy">
<option selected="selected">正常</option>
<option>反常</option>
</select>
<input name="txt1" onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name="txt2" onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name="txt3" onfocus="mm()" onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
</form> <script language="JavaScript"><!--
function mm()
{
with(document.hrong)
{
if (yyy.options[yyy.selectedIndex].text == '正常') {
if (!txt1.value || !txt2.value){
alert('有一项为空, 不予计算!');
return;
}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
else if (yyy.options[yyy.selectedIndex].text == '反常') {
txt3.value = 0;
}
}
}
//--></script>偶都可以~
没测试正常情况
<html>
<head></head><body >
<form name=hrong>
<select name="yyy" id="yyy" >
<option selected value="1">正常</option>
<option value="0">反常</option>
</select>
</font>
<input name=txt1 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt2 onkeydown="if(event.keyCode==13)event.keyCode=9"><br>
<input name=txt3 onkeydown="if(event.keyCode==13)event.keyCode=9" onfocus="mm()"><br>
</form>
<SCRIPT LANGUAGE="JavaScript"><!--
function mm()
{
var txt3=document.getElementById("txt3");
var txt1=document.getElementById("txt1");
var txt2=document.getElementById("txt2");
if(document.getElementById("yyy").value=="0"){
alert("反常");
txt3.value=0;}
else if(document.getElementById("yyy").value=="1"){
if(!txt1.value || !txt2.value){alert('有一项为空, 不予计算!'); return;}
var n1 = parseInt(txt1.value)? parseInt(txt1.value) : 0;
var n2 = parseInt(txt2.value)? parseInt(txt2.value) : 0;
txt3.value = n1 + n2;
}
}
//--></SCRIPT>
</body>
</html>