Javascript 使脚本在加载或类似情况下工作，而不是在更改时工作

我有一个简单的js脚本，用于根据从下拉列表中选择的值加载文本框

问题是：它只在更改时加载，如果加载时选择的值不是0，我需要在加载页面时加载它。这个脚本对我来说非常混乱，所以我无法准确地找出需要更新的地方

剧本：

function addInput(){
var arr = [
"<p style='text-align:center;'>Reward 1: <input type='text' name='rew1' id='rew1' value='<?php echo $connt['reward_1'] ?>'></p>",
"<p style='text-align:center;'>Reward 2: <input type='text' name='rew2' id='rew2' value='<?php echo $connt['reward_2'] ?>'></p>",
"<p style='text-align:center;'>Reward 3: <input type='text' name='rew3' id='rew3' value='<?php echo $connt['reward_3'] ?>'></p>",
"<p style='text-align:center;'>Reward 4: <input type='text' name='rew4' id='rew4' value='<?php echo $connt['reward_4'] ?>'></p>",
"<p style='text-align:center;'>Reward 5: <input type='text' name='rew5' id='rew5' value='<?php echo $connt['reward_5'] ?>'></p>",
"<p style='text-align:center;'>Reward 6: <input type='text' name='rew6' id='rew6' value='<?php echo $connt['reward_6'] ?>'></p>",
"<p style='text-align:center;'>Reward 7: <input type='text' name='rew7' id='rew7' value='<?php echo $connt['reward_7'] ?>'></p>",
"<p style='text-align:center;'>Reward 8: <input type='text' name='rew8' id='rew8' value='<?php echo $connt['reward_8'] ?>'></p>",
"<p style='text-align:center;'>Reward 9: <input type='text' name='rew9' id='rew9' value='<?php echo $connt['reward_9'] ?>'></p>",
"<p style='text-align:center;'>Reward 10: <input type='text' name='rew10' id='rew10' value='<?php echo $connt['reward_10'] ?>'></p>",
];
var el = document.getElementById('select');
var div = document.getElementById('rewards');
div.style.display = "block";
while(div.hasChildNodes()) { div.removeChild(div.childNodes[0]); }

if(el.selectedIndex > 0) {
for(var i = 0; i<el.options[el.selectedIndex].value; i++) {
div.innerHTML = div.innerHTML + arr[i];
}
}

}

函数addInput（）{
var arr=[
“