购买物品的累加计算

- 中国WEB开发者网络 (http://www.webasp.net)
-- 网页特效 (http://www.webasp.net/javascript/)
--- 购买物品的累加计算 (http://www.webasp.net/javascript/1/732.htm)
-- 发布日期： 2005-07-01
<!-- 网页特效代码由[中国WEB开发者网络:http://www.ChinaWebDev.com]提供！ -->
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<!-- 第 1 步： -->
<!-- 把<BODY>中的属性代码改为： -->

<BODY onLoad="InitForm();">



<!-- 第 2 步： -->
<!-- 把下面的代码加到<BODY></BODY>区域中： -->

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
<!-- begin cloaking from non-JavaScript browsers.

// TITLE: Order Form with Checkbox Item Selection
// An order form which utilizes checkboxes for making a selection. This method only allows
// one quantity of any item to be ordered.
// Script updates the order total as the visitor checks and unchecks the selections.
// Also note that the order total can not be manually altered by the visitor.

// Custom scripting by Paul DeBrino of Infinity Research and Development, Inc.
// We also have a netscrape version for purchase, which works with both NS and IE.
// For other scripts, or to place an order for customized scripts such as
// on-line form scripting, please contact the owner via Email at: info @ infinity-rd.com
// If you wish to use this script, kindly keep these comments and (C)opyright within the
// source code. Permission granted for http://javascript.internet.com to publish this script.

//Define global form total:
var form_total=0;

//Define function to manipulate the form total per item selected/deselected:
function CheckChoice(whichbox)
{

//This code will dump all Document Object Model properties for the active checkbox:
//Remove the "//" marks *after* "start of commented section ...
// up to but *not* including "end of commented section" to make this work.
//START OF COMMENTED SECTION:
//for (xx in whichbox)
// {
// document.write(xx);
// document.write(' = ');
// document.write(eval('whichbox.'+xx));
// //UNCOMMENT THE FOLLOWING LINES IF YOU ALSO WANT TO DUMP THE CHILD OBJECTS:
// //if (eval('whichbox.'+xx)=='[object]')
// //{ document.write('**Begin child: ');
// // for (zz in eval('whichbox.'+xx))
// // { document.write(zz);
// // document.write(' = ');
// // document.write(eval('whichbox.'+xx+zz));
// // document.write(', ');
// // }
// // document.write(':End child**');
// //}
// document.write('<br>');
// }
// END OF COMMENTED SECTION.

//If box was checked, accumulate the checkbox value as the form total,
//Otherwise, reduce the form total by the checkbox value:
if (whichbox.checked == false)
{ form_total -= eval(whichbox.value); }
else { form_total += eval(whichbox.value); }

//Re-set displayed total on form:
document.myform.total.value = '$'+eval(form_total);

}

//Define function to init the form on reload:
function InitForm()
{
//Reset the displayed total on form:
document.myform.total.value='$0';

//Set all checkboxes on form to unchecked:
for (xx=0; xx < document.myform.elements.length; xx++)
{
if (document.myform.elements[xx].type == 'checkbox')
{
document.myform.elements[xx].checked = false;
}
}
}


// end cloaking -->
// End -->
</script>
<form method="POST" name="myform">
<font face=Arial>
商品一 $15.25
<input type="checkbox" name="Steak" value=15.25 onclick="CheckChoice(this);">
商品二 $12.39
<input type="checkbox" name="Chicken" value=12.39 onclick="CheckChoice(this);">
商品三 $18.75
<input type="checkbox" name="Sushi" value=18.75 onclick="CheckChoice(this);">
<br><br>
<font>
花费总计: <input type="text" name="total" readonly onFocus="this.blur();">
</font>
</font>
</form>

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