function rev4calc(radius, strut, A, B, C, D, E, F,  struta, strutb, strutc, strutd, strute, strutf) {
	if(document.revform.strut.value == null || document.revform.strut.value <= 0){
		alert("Strut Length must be a positive value");
              return} 
      if(document.revform.choose.value == "A") {
	    radius = document.revform.strut.value/.25318
		}
	  else if (document.revform.choose.value == "B") {
	    radius = document.revform.strut.value/.29524
       }	
	  else if (document.revform.choose.value == "C") {
	    radius = document.revform.strut.value/.29453
       }	
	  else if (document.revform.choose.value == "D") {
	    radius = document.revform.strut.value/.31287
       }	
	  else if (document.revform.choose.value == "E") {
	    radius = document.revform.strut.value/.32492
       }	   
	  else  {
	    radius = document.revform.strut.value/.29859
       }	 
		 
		document.result.struta.value = radius*.25318
        document.result.struta.value = document.result.struta.value.substring(0,6)
        
        document.result.strutb.value = radius*.29524
        document.result.strutb.value = document.result.strutb.value.substring(0,6)     
		
		document.result.strutc.value = radius*.29453
        document.result.strutc.value = document.result.strutc.value.substring(0,6)    
		
		document.result.strutd.value = radius*.31287
        document.result.strutd.value = document.result.strutd.value.substring(0,6)    
		
		document.result.strute.value = radius*.32492
        document.result.strute.value = document.result.strute.value.substring(0,6)       
		
		document.result.strutf.value = radius*.29859
        document.result.strutf.value = document.result.strutf.value.substring(0,6)    
		
		document.result.radius.value = radius
		document.result.radius.value = document.result.radius.value.substring(0,7)
return   
}