// JavaScript Document
window.onload=disableUploadField;

function disableUploadField (){
    disableImageUploadField('img','video_link');
    disableVideoUploadField('img','video_link');
}

function disableImageUploadField(imageFieldId, videoFieldId) {
    if( document.getElementById(imageFieldId).disabled != true ) {
        document.getElementById(imageFieldId).disabled=true;
    }
    if( document.getElementById(videoFieldId).disabled != false ) {
        document.getElementById(videoFieldId).disabled=false;
    }
}

function disableVideoUploadField(imageFieldId, videoFieldId) {
    if( document.getElementById(imageFieldId).disabled != false ) {
        document.getElementById(imageFieldId).disabled=false;
    }
    if( document.getElementById(videoFieldId).disabled != true ) {
        document.getElementById(videoFieldId).disabled=true;
    }
}