当访问者输入文本字段中的访问者键入颜色代码时，自动更改样本边框

I would like to know how to auto change sample border when visitor key-in color code in input textfield at:

Do you have a particular border colour you would like?

input name="ContentInclude:borderspecs" type="text" maxlength="200" id="ContentInclude_borderspecs" tabindex="5" style="width:500px"

https://advertiser.seek.com.au/advertisers/catalogue/templaterequest.ascx

The sample code start with: begin sample template

The simplest solution:

<input name="ContentInclude:borderspecs" type="text" maxlength="200" 
    id="ContentInclude_borderspecs" tabindex="5" style="width:500px" 
    onkeyup="javascript:changeBorderColor(this);">

JS code:

<script>
function changeBorderColor(elem){
    var template = document.getElementById('sampletemplate');
    if (elem.value.match(/^\#([\dabcdef]{3}|[\dabcdef]{6})$/i)) { // HEX code
        template.style.borderColor = elem.value;
    }
    // more else if to match other possible values
    else { // reset to default
        template.style.borderColor = null; // or "black"
    }
}
</script>

// edited so it changes the color of template preview div#sampletemplate