The previous developer who has been working here used javascript on some forms and they're not functioning properly when opened with IE (any version)

The link to the form: [LINK]

On firefox, it doesn't prompt any error and as you can see, it auto selects "Lebanon" as a country and it selects the date with 3 days in between till the return date. These don't work on IE, it just shows blank.

Here is the javascript used.
Code:
$cargroup=$_GET["group"];
$countryofrental = $_GET["cor"];
$countryofresidence = $_GET["corofres"];
$daycoll = date("d") + 2;
$mthcoll = $_GET["monthcoll"];
$yearcoll = date("Y");
$hr = $_GET["hr"];

$dayret = date("d") + 5;
$mthret = date("m");
$yearret = date("Y");
echo '
<script type="text/javascript">
function setvalue(){
var x=document.getElementById("cargroup");
x.value='.$cargroup.'
}
function setvaluectr(){
var x=document.getElementById("countryofrental");
x.value='.$countryofrental.'
}
function setvaluectrofres(){
var x=document.getElementById("countryofresidence");
x.value='.$countryofresidence.'
}
function setdaycoll(){
var x=document.getElementById("daycoll");
x.value='.$daycoll.'
}
function setmthcoll(){
var x=document.getElementById("monthcoll");
x.value='.$mthcoll.'
}
function setyearcoll(){
var x=document.getElementById("yearcoll");
x.value='.$yearcoll.'
}
function sethrcoll(){
var x=document.getElementById("hrcoll");
x.value='.$hr.'
}


function setdayret(){
var x=document.getElementById("dayret");
x.value='.$dayret.'
}
function setmthret(){
var x=document.getElementById("monthret");
x.value='.$mthret.'
}
function setyearret(){
var x=document.getElementById("yearret");
x.value='.$yearret.'
}
function sethrret(){
var x=document.getElementById("hrret");
x.value='.$hr.'
}
</script>';
and here is the call page
Code:
<div align="left" style="width:100%" class="componentheading">{formtitle}</div>

<div align="left" style="width:80%;" id="rsform-div">
<div id="rsform-mandatory">* Mandatory fields</div><br>
<form name="{formname}" id="{formname}" id="rsform-form" method="post" action="{action}" {enctype}>
	<table width="100%" border="0" cellpadding="0" cellspacing="0" class="forme">
	{formfields}
	</table>
</form>
</div>
<script type="text/javascript">
setvalue();
setvaluectr();
setvaluectrofres();
setdaycoll();
setmthcoll();
setyearcoll();
sethrcoll();

setdayret();
setmthret();
setyearret();
sethrret();
</script>
Any advise? Thanks.