function restrictSelection(optRef) {

	if (optRef == "v_50_5") {   	
		restrictSelectionType();
	} else if  (optRef == "v_50_10") {
		restrictSelectionThinLense();
	} else if (optRef == "v_50_11") {
		restrictSelectionPolarised();
	} else if (optRef == "v_50_13") {
		restrictSelectionLightReaction();
	} 	
}


function restrictSelectionType()	{
	typesel = document.getElementsByName('v_50_5')[0];
	polarised = document.getElementsByName('v_50_11')[0];
	thinlenses = document.getElementsByName('v_50_10')[0];
	lightreact = document.getElementsByName('v_50_13')[0];	
	tints = document.getElementsByName('v_50_14')[0];
	ar  = document.getElementsByName('v_50_17')[1];
	uv = document.getElementsByName('v_50_15')[1];
	
	if (typesel.value == 4) {   		
   		polarised.value = 1;
   		polarised.disabled=true;   		
   		
   		thinlenses.value=1;
   		thinlenses.options[2].disabled = true;
   		thinlenses.options[3].disabled = true;   		
   } else {
   		polarised.value = 1;
   		polarised.disabled=false;   		
   		
   		lightreact.value = 1;
   		lightreact.disabled=false;   		
   		
   		tints.value = 1;
   		tints.disabled=false;   		
   		
   		ar.disabled=false;
   		uv.disabled=false;
   		
   		thinlenses.value=1;
   		thinlenses.options[2].disabled = false;
   		thinlenses.options[3].disabled = false;   
   }	
	
}


function restrictSelectionThinLense()	{	
	thinlenses = document.getElementsByName('v_50_10')[0];	
	polarised = document.getElementsByName('v_50_11')[0];
	typesel = document.getElementsByName('v_50_5')[0];
	lightreact = document.getElementsByName('v_50_13')[0];	
	
	if (thinlenses.value == 1) {   					
		if (typesel.value != 4) {   								
   		polarised.value = 1;
   		polarised.disabled=false;   		   		   		
   		lightreact.value = 1;
		   lightreact.disabled=false;     		
   	}
   } else {
   		polarised.value = 1;
   		polarised.disabled=true;   		
   		if (thinlenses.value == 3 || thinlenses.value == 4) {   					
		   		lightreact.value = 1;
		   		lightreact.disabled=true;   		
   		}	else {
   				lightreact.value = 1;
		   		lightreact.disabled=false;  
		   } 		
  		
   }		
   
}


function restrictSelectionPolarised()	{
	polarised = document.getElementsByName('v_50_11')[0];		
	lightreact = document.getElementsByName('v_50_13')[0];	
	tints = document.getElementsByName('v_50_14')[0];
	
	ar  = document.getElementsByName('v_50_17')[1];
	uv = document.getElementsByName('v_50_15')[1];
	
	if (polarised.value  != 1) {
   		lightreact.value = 1; 
   		lightreact .disabled=true;
   		tints.value = 1; 
   		tints.disabled=true;   		

   		uv.checked = false;
   		uv.disabled = true;
   		
   		ar.checked = false
   		ar.disabled =true;   		
   		
   } else {   
   		lightreact.value = 1; 
			lightreact .disabled=false;
			tints.value = 1; 
			tints.disabled=false;   		
   		
   		uv.value= 1;
			uv.disabled = false;
					
			ar.checked = false;
   		ar.disabled =false;   		
   }
}

function restrictSelectionLightReaction()	{	
	lightreact = document.getElementsByName('v_50_13')[0];		
	polarised = document.getElementsByName('v_50_11')[0];		
	tints = document.getElementsByName('v_50_14')[0];
	typesel = document.getElementsByName('v_50_5')[0];
	
	ar  = document.getElementsByName('v_50_17')[1];
	uv = document.getElementsByName('v_50_15')[1];
	
	if (lightreact.value  != 1) {
   		polarised.value = 1; 
   		polarised.disabled=true;
   		tints.value = 1; 
   		tints.disabled=true;   		
   		
   		uv.checked = false;
   		uv.disabled = true;
   		
   		
   }  else {
   		if (typesel.value != 4) {   								
			   		polarised.value = 1;
			   		polarised.disabled=false;   		   		   				
   		}
			tints.value = 1; 
			tints.disabled=false;   		
			
			uv.checked = false;
			uv.disabled = false;
						
   }
     
}