<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页 </title>
</head>
<script type="text/javascript" language="javascript">
var test = 0;
var test2 = 0;
function set1(obj,maxi,demo)
{
if (obj=="clear"){
document.getElementById(demo).value="";
eval(demo +="= 0;")
return;
};
eval(demo + "++");
if(eval(demo) >= maxi) {alert("最多只能选择"+(maxi-1)+"个");return;}
document.getElementById(demo).value += obj + "/";
}
</script>
<body>
<form id="form1" >
<input type="text" value="" name="test" id="test"/>
<input type="text" value="234/455/" name="test2" id="test2"/>
<select name="select" id="select" onchange="set1(this.options[this.selectedIndex].value,3,'test')">
<option value="">专业领域2</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="789">789</option>
<option value="clear">清空重选</option>
</select>
<select name="select2" id="select2" onchange="set1(this.options[this.selectedIndex].value,4,'test2')">
<option value="">专业领域3</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="1111">1111</option>
<option value="2222">2222</option>
<option value="33333">33333</option>
<option value="789">789</option>
<option value="aaa">aaa</option>
<option value="clear">清空重选</option>
</select>
</form>
</body>
</html> 文本框为空时 上面的运行正常
但如果文本本身就已经有了值 例如第二个文本框,此时就要先做下判断,再决定是否可以添加值
我想添加
//ttt=document.getElementById(demo).value.split('/')[maxi-2]
//if (ttt!=""){alert("你已经选择了"+(maxi-1)+"个");return;} 但是不行
还有
eval(demo +="= 0;")和
eval(demo + "++");
是什么意思啊,我看不懂?往高手指点
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页 </title>
</head>
<script type="text/javascript" language="javascript">
var test = 0;
var test2 = 0;
function set1(obj,maxi,demo)
{
if (obj=="clear"){
document.getElementById(demo).value="";
eval(demo +="= 0;")
return;
};
eval(demo + "++");
if(eval(demo) >= maxi) {alert("最多只能选择"+(maxi-1)+"个");return;}
document.getElementById(demo).value += obj + "/";
}
</script>
<body>
<form id="form1" >
<input type="text" value="" name="test" id="test"/>
<input type="text" value="234/455/" name="test2" id="test2"/>
<select name="select" id="select" onchange="set1(this.options[this.selectedIndex].value,3,'test')">
<option value="">专业领域2</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="789">789</option>
<option value="clear">清空重选</option>
</select>
<select name="select2" id="select2" onchange="set1(this.options[this.selectedIndex].value,4,'test2')">
<option value="">专业领域3</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="1111">1111</option>
<option value="2222">2222</option>
<option value="33333">33333</option>
<option value="789">789</option>
<option value="aaa">aaa</option>
<option value="clear">清空重选</option>
</select>
</form>
</body>
</html> 文本框为空时 上面的运行正常
但如果文本本身就已经有了值 例如第二个文本框,此时就要先做下判断,再决定是否可以添加值
我想添加
//ttt=document.getElementById(demo).value.split('/')[maxi-2]
//if (ttt!=""){alert("你已经选择了"+(maxi-1)+"个");return;} 但是不行
还有
eval(demo +="= 0;")和
eval(demo + "++");
是什么意思啊,我看不懂?往高手指点
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页 </title>
</head>
<script type="text/javascript" language="javascript">
function set1(obj,maxi,demo)
{
if (obj=="clear"){
document.getElementById(demo).value="";
return;
};
var sVal = document.getElementById(demo).value;
var aItem = sVal.split("/");
if(aItem.length >= maxi) {alert("最多只能选择"+(maxi-1)+"个");return;}
document.getElementById(demo).value += obj + "/";
}
</script>
<body>
<form id="form1" >
<input type="text" value="" name="test" id="test"/>
<input type="text" value="234/455/" name="test2" id="test2"/>
<select name="select" id="select" onchange="set1(this.options[this.selectedIndex].value,3,'test')">
<option value="">专业领域2</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="789">789</option>
<option value="clear">清空重选</option>
</select>
<select name="select2" id="select2" onchange="set1(this.options[this.selectedIndex].value,4,'test2')">
<option value="">专业领域3</option>
<option value="123">123</option>
<option value="234">234</option>
<option value="456">456</option>
<option value="1111">1111</option>
<option value="2222">2222</option>
<option value="33333">33333</option>
<option value="789">789</option>
<option value="aaa">aaa</option>
<option value="clear">清空重选</option>
</select>
</form>
</body>
</html>