function checkSamples() {
	var count = 0;
	if (document.samples.FP_Blade_D4.checked) {
		count++;
	}
	if (document.samples.FP_Blade_D11.checked) {
		count++;
	}

	if (document.samples.FP_Blade_11.checked) {
		count++;
	}

	if (document.samples.FP_Blade_20.checked) {
		count++;
	}

	if (document.samples.FP_Blade_25.checked) {
		count++;
	}

	if (document.samples.FP_Blade_40.checked) {
		count++;
	}

	if (document.samples.FP_Blade_B_20.checked) {
		count++;
	}

	if (count == 0) {
		alert('Please a sample');
		return false;
	}
	if (count > 3) {
		alert('Please a maximum of 3 samples');
		return false;
	}
	
	return true;
}