/*
Enable/disable fields as required. 
And use ValidatorValidate to re-evaluate fields afterwards.
@param fieldNumberToEnable is either 1 or 2 depending on which field should be enabled.
@param field1 a field to either enable or disable.
@param field2 a field to either enable or disable.
@param field1Validator holds clientID for field1's CustomValidator.
@param field2Validator holds clientID for field2's CustomValidator.
*/
function enableOnlyValidField(fieldNumberToEnable, field1, field2, field1Validator, field2Validator) {
	if(fieldNumberToEnable == 1) {
        field1.disabled = false;
		field2.disabled = true;
		field2.value = "";
        ValidatorValidate(field1Validator);
        ValidatorValidate(field2Validator);
	} else {
		field1.disabled = true;
		field2.disabled = false;
		field1.value = "";
        ValidatorValidate(field1Validator);
        ValidatorValidate(field2Validator);
	}
}

/*
Use this function to enable or disable a single validator of the supplied field.
@param field the field for which to enable/disable validation.
@param isEnable indicate if validation should be turned on/off.
*/
function setValidationEnabled(field, isEnabled) {
	var fieldValidator = getFieldValidator(field);
	if (fieldValidator != null) {
		ValidatorEnable(fieldValidator, isEnabled);
	}
}

/*
Find a single validator associated with a given field.
@param field the field for which to find a validator.
@return a MS client side validator object.
*/
function getFieldValidator(field) {
	if (typeof(Page_Validators) == 'object') {
		for (i=0; i<Page_Validators.length; i++) {
			if (Page_Validators[i].controltovalidate == field.name) {
				return Page_Validators[i];
			}
		}
	}
}