function validate(docname)
{

var i;
var getval=docname.value;

// Validate data:- parse string to check whether it contains
// characters other than numbers and one decimal
var count_deci=0;
var flag=0;
// parse through the data
for(i=0;i<getval.length;i=i+1)
{ if((getval.charAt(i) >= "0" && getval.charAt(i)  <= "9") || (getval.charAt(i) == "."))
	{	// if decimal 
	   if(getval.charAt(i) == ".")
	     {
	      count_deci=count_deci+1;
	      // to check entries of the type X.
	      if(getval.charAt(i+1)=="")
	      { 
	        alert("Wrong entry"); 
	        docname.value="";
	        docname.focus();
	        flag=1;
	        break;
	      }
	     }
	      // check if there is more than one decimal
	      if(count_deci>1)
		   { alert("Illegal Data");
			 docname.value="";
			 docname.focus();
			 flag=1;
			 break;
		   }
	}	   
	// executed if data contains alphabets or special chars
	else
	{ alert("Invalid Entry");
	  docname.value="";
	  docname.focus();
	  flag=1;
	  break;
	}		

}
}






function calculate(docname)
{
var totalrecords;

// obtain the count of records retrieved
totalrecords=16
// declare variables

var dimension_name=new Array(totalrecords);
var dimension_value=new Array(totalrecords);
var value_obtained=new Array(totalrecords);
var area;
var count=0;
var index;

//
// All values relative to sq. feet - constants
//

dimension_name[0]="Aankadam";
dimension_value[0]=0.0138908;

dimension_name[1]="Acres";
dimension_value[1]=0.00002295;

dimension_name[2]="Ares";
dimension_value[2]=0.0009293;

dimension_name[3]="Bhighas";
dimension_value[3]=0.0000573;

dimension_name[4]="Biswa";
dimension_value[4]=0.0000028;

dimension_name[5]="Cents";
dimension_value[5]=0.002296;

dimension_name[6]="Chataks";
dimension_value[6]=0.0022222;

dimension_name[7]="Grounds";
dimension_value[7]=0.0004166;

dimension_name[8]="Guntha";
dimension_value[8]=0.0009182;

dimension_name[9]="Hectares";
dimension_value[9]=0.0000092;

dimension_name[10]="Kanal";
dimension_value[10]=0.0001852;

dimension_name[11]="Kottha";
dimension_value[11]=0.0013888;

dimension_name[12]="Rood";
dimension_value[12]=0.0000918;

dimension_name[13]="Square Feet";
dimension_value[13]=1;

dimension_name[14]="Square Meter";
dimension_value[14]=0.093;

dimension_name[15]="Square Yards";
dimension_value[15]=0.1111111112;

//
// Get dimension values
//
for(i=0;i<totalrecords;i=i+1)
{   
	value_obtained[i]=docname[i].value;
}
//
// check for more than one entry :- count keeps tab of that.
// index is used to track the field in which user has entered
// data
// 
for(i=0;i<totalrecords;i=i+1)
{
   if(value_obtained[i]!=0)
   {	index=i;
        count=count+1;
   }
}

//
// more than one entry ?
//
if(count>1)
{   
    // display error message 
    alert("Wrong number of data entries");
	// set focus to first field
	docname.area0.focus();
	// make all fields null
	for(i=0;i<totalrecords;i=i+1)
	{
		docname[i].value="";
	}
	
}
//
// if there is only one entry 
//
else
{
  
	
	
	for(i=0;i<totalrecords;i=i+1)
	{	// it is unnecessary to calculate the indexed value 
		// again
		if(i==index)
		continue;
		else
		{
	value_obtained[i]=value_obtained[index]*dimension_value[i]/dimension_value[index];
		
		}			
	}
	
	// place values back in each field
	for(i=0;i<totalrecords;i++)
	{
		docname[i].value=value_obtained[i];
	}
	
//}// end of inner else
}// end of outer else
return false;
}// end of function


function clearbox2(docname)
{
var totalrecords;

// obtain the count of records retrieved
totalrecords=16
for(i=0;i<totalrecords;i++)
docname[i].value="";
docname.area0.focus();
return false;
}