function show_categs(num)
{
    if(num == 5) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = false;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = false;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = false;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = false;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = false;
	}
    if(num == 4) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = false;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = false;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = false;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = false;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = true;
	}
    if(num == 3) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = false;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = false;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = false;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = true;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = true;
	}
    if(num == 2) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = false;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = false;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = true;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = true;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = true;
	}
    if(num == 1) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = false;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = true;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = true;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = true;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = true;
	}
    if(num == 0) {
		if(document.getELementById('cat1') != null) document.getELementById('cat1').enabled = true;
		if(document.getELementById('cat2') != null) document.getELementById('cat2').enabled = true;
		if(document.getELementById('cat3') != null) document.getELementById('cat3').enabled = true;
		if(document.getELementById('cat4') != null) document.getELementById('cat4').enabled = true;
		if(document.getELementById('cat5') != null) document.getELementById('cat5').enabled = true;
	}
}