更改下拉列表中隐藏的Paypal值

Question

我有两个下拉

这是使用Paypal购买短袖或长袖衬衫表格的一部分。

短袖是一个价格。长袖是另一个价格。这很管用。使用隐藏值，我可以更改2XL和3XL短袖衬衫的价格。这很管用。

javascript用于更改2XL和3XL长袖衬衫的价格。这也很有效。我遇到的问题是将option_select值改为"LS 2XL"或"LS 3xL"，而不是"SS 2XL"one_answers"SS 3xL"(以及其他长袖尺码(。

我不精通javascript，但我通常能把足够多的东西拼凑在一起，使其正常工作。这件事把我难住了。如有任何使用javascript的帮助，我们将不胜感激。

function changeHiddenInput(objDropDown) {
var upcharge2XL = document.getElementById("hiddenvalue2XL");
var upcharge3XL = document.getElementById("hiddenvalue3XL");
upcharge2XL.value = 20.00;
upcharge3XL.value = 21.00;
}

<select name="amount" size="1" id="Combobox1"  onchange="changeHiddenInput(this)">
<option value="15.00">Short Sleeve</option>
<option value="18.00">Long Sleeve</option>
</select><br/>
<select name="os0" size="1" id="Combobox2">
<option selected>Select Size</option>
<option value="SS Small">Small</option>
<option value="SS Medium">Medium</option>
<option value="SS Large">Large</option>
<option value="SS XL">XL</option>
<option value="SS 2XL">2XL + $2</option>
<option value="SS 3XL">3XL + $3</option>
<option value="--------">--------</option>
<option value="SS Youth Small">Youth Small</option>
<option value="SS Youth Medium">Youth Medium</option>
<option value="SS Youth Large">Youth Large</option>
</select><br/>
Hidden Paypal Values
<input type="hidden" name="option_select0" value="SS 2XL" id="hiddensize2XL">
<input type="hidden" name="option_amount0" value="17.00" id="hiddenvalue2XL">
<input type="hidden" name="option_select1" value="SS 3XL" id="hiddensize3XL">
<input type="hidden" name="option_amount1" value="18.00" id="hiddenvalue3XL">

Answer 1

我想你是这个意思吧？

document.getElementById("pp1").addEventListener("submit",function(e) {
e.preventDefault(); // remove this line when finished testing
const sleeve = document.getElementById("Combobox1").value;
const size = document.getElementById("Combobox2").value;
if (sleeve === "" || size === "") {
alert("Please choose sleeves and size")
e.preventDefault(); // stop submission
}
let amt = sleeve === "SS" ? 15 : 17;
if (size === "2XL") amt += 2;
else if (size === "3XL") amt += 3;
document.getElementById("hiddensize2XL").value=size
document.getElementById("hiddensize3XL").value=size
document.getElementById("hiddenvalue2XL").value = amt.toFixed(2)
document.getElementById("hiddenvalue3XL").value = amt.toFixed(2);
})

<select name="amount" size="1" id="Combobox1">
<option value="" selected>Sleeves</option>
<option value="SS">Short Sleeve</option>
<option value="LS">Long Sleeve</option>
</select><br/>
<select name="os0" size="1" id="Combobox2">
<option value="" selected>Select Size</option>
<option value="Small">Small</option>
<option value="Medium">Medium</option>
<option value="Large">Large</option>
<option value="XL">XL</option>
<option value="2XL">2XL + $2</option>
<option value="3XL">3XL + $3</option>
<option value="--------">--------</option>
<option value="Youth Small">Youth Small</option>
<option value="Youth Medium">Youth Medium</option>
<option value="Youth Large">Youth Large</option>
</select><br/>
Hidden Paypal Values
<form id="pp1">
<input type="text" name="option_select0" value="" id="hiddensize2XL">
<input type="text" name="option_amount0" value="17.00" id="hiddenvalue2XL">
<input type="teyxt" name="option_select1" value="" id="hiddensize3XL">
<input type="teyt" name="option_amount1" value="18.00" id="hiddenvalue3XL">
<input type="submit" />
</form>