function validateEmpty(fldId) {
	
	var fld = document.getElementById(fldId);
	var error = false;
	
	if (fld.value.length == 0) {
		
		error = true;
		
	}
	
	return error;
	
}


function validateUsername(fldId) {
	
	var illegalChars = /\W/; // allow letters, numbers, and underscores	
	var fld = document.getElementById(fldId);
	var error = false;
	
	if (fld.value == "") {
		
		error = 'EMPTY';
		
	} else if ((fld.value.length < 5) || (fld.value.length > 255)) {
		
        error = 'LENGTH';
		
	} else if (illegalChars.test(fld.value)) {
		
        error = 'ILLEGAL';
		
	}
	
	return error;
	
}


function validatePassword(fldId) {
	
	var illegalChars = /[\W_]/; // allow only letters and numbers	
	var fld = document.getElementById(fldId);
	var error = false;
	
	if (fld.value == "") {
		
        error = 'EMPTY';
        
    } else if ((fld.value.length < 6) || (fld.value.length > 32)) {
    	
        error = 'LENGTH';
        
    } else if (illegalChars.test(fld.value)) {
    	
        error = 'ILLEGAL';
        
    }
    
    return error;
    
}  


function trim(s) {
	
	return s.replace(/^\s+|\s+$/, '');
	
}


function validateEmail(fldId) {
	
	var fld = document.getElementById(fldId);
	var error = false;    
    var tfld = trim(fld.value); // value of field with whitespace trimmed off
    var emailFilter = /^[^@]+@[^@.]+\.[^@]*\w\w$/ ;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
    
    if (fld.value == "") {
    	
        error = 'EMPTY';
        
    } else if (!emailFilter.test(tfld)) {
    	
        error = 'INVALID';
        
    } else if (fld.value.match(illegalChars)) {
    	
        error = 'ILLEGAL';
        
    }
	    
    return error;
    
}