Using java script to check Signature and Photo

Check for Photo

function ValidatePhoto() {
        var msg = "";
        var bIsValid = true;        
        var uploadedFile = document.getElementById('MainContent_FileUploadPhoto');
        if (uploadedFile.files[0].size > 51200 || uploadedFile.files[0].size < 20480) // greater than 512KB
        {
            uploadedFile.outerHTML = uploadedFile.outerHTML;
            alert('File size is not as the prescribe size.');
            bIsValid = false;
        }
        //On Success
        return true;

    }



check for Signature
function ValidateSignature() {
        var msg = "";
        var bIsValid = true;
        var uploadedFile = document.getElementById('MainContent_FileUploadSignature');
     if (uploadedFile.files[0].size > 20480 || uploadedFile.files[0].size < 10240) // greater than 512KB
        {
            uploadedFile.outerHTML = uploadedFile.outerHTML;
            alert('File size is not as the prescribe size.');
            bIsValid = false;
        }
        //On Success
        return true;
    }