<select multiple size=10>
<option>1
<option>2
<option>3
<option>4
<option>5
<option>6
<option>7
</select>
<button onclick="alert(selectedLength(previousSibling))">查看选择的个数</button>
<SCRIPT LANGUAGE="JavaScript">
function selectedLength(sel) {
var count = 0;
for (var i=0;i<sel.length;i++) {
if(sel[i].selected) count++;
}
return count;
}
</SCRIPT>
<option>1
<option>2
<option>3
<option>4
<option>5
<option>6
<option>7
</select>
<button onclick="alert(selectedLength(previousSibling))">查看选择的个数</button>
<SCRIPT LANGUAGE="JavaScript">
function selectedLength(sel) {
var count = 0;
for (var i=0;i<sel.length;i++) {
if(sel[i].selected) count++;
}
return count;
}
</SCRIPT>
function getNum() {
j=0;
for (i=0;i<s.options.length;i++) {
if(s.options[i].selected) {
j=j+1;
}
}
alert(j);
}
</script>
<select name="s" multiple>
<option value="0">000</option>
<option value="1">001</option>
<option value="2">002</option>
<option value="3">003</option>
<option value="4">004</option>
</select>
<input type="button" value="²é¿´" onclick="return getNum()">
function opentrain(){
var j = 0;
for(i = 0;i<9;i++){
if(form3.dmdepart[i].selected==true){
j++;
}
}
alert(j);
}
</script>
<form3>
<select name="dmdepart" multiple size="3">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
</select>
</form3>
<script>
function alertNum(){
with(form1){
var i = 0;
for(var j=0;j<select1.length;j++){
if(select1.options[j].selected){
i++;
}
}
return i;//这个就是选种的数量,
}
}
</script>
<form1 onSubmit="alertNum()">
<select name="select1" size="10" multiple id="select1">
<option value="0">a</option>
<option value="1">b</option>
<option value="2">c</option>
<option value="3">d</option>
……
<option value="n">n</option>
</select>
……
</form>