function card1_check()

{

	var str=document.forms[0].elements[0].value;

	if( str == "4 2/3" )

	{

		self.parent.top.location="card1x.html";

		return false;

	}

	else

	{

		return CardErrorCheck( str, eval(4+2/3) );

	}

}	



function card2_check()

{

	var str=document.forms[0].elements[0].value;

	if(str == "25 1/2")

	{

		self.parent.top.location="card2x.html";

		return false;

	}

	else

	{

		return CardErrorCheck( str, 25.5 );

	}

}



function card3_check()

{

	var str=document.forms[0].elements[0].value;

	if(str == "24")

	{

		self.parent.top.location="card3x.html";

		return false;

	}

	else

	{

		return CardErrorCheck( str, 24);

	}

}



function card4_check()

{

	var str=document.forms[0].elements[0].value;

	if(str == "4 1/2")

	{

		self.parent.top.location="card4x.html";

		return false;

	}

	else

	{

		return CardErrorCheck( str, 4.5 );

	}

}



function blq_frac3_check()

{

	var str=document.forms[0].elements[0].value;

	if(str == "12852")

	{

		self.parent.top.location="continued1.html";

		return false;

	}

	else

	{

		return CardErrorCheck( str, 12852);

	}

}

function CardErrorCheck( str, decimalAnswer )

{

	if(IsAFraction(str))

	{

		if(ParseFraction(str) == decimalAnswer)

		{

			alert("You must enter your answer as a simplified mixed number.");

		}

		else

		{

			alert("That isn't quite right.");

		}

	}

	else

	{

		alert("You must enter your answer in fractional notation.");

	}

	return false;

}





//Again, the fraction functions.

function IsAFraction( str )

{

	var isFraction=true;

	if( str.length == 0 )

		return false;



	for( var i = 0; i < str.length; i ++ )

	{

		if( !IsValidChar(str[i]) )

		{

			isFraction = false;

		}

	}

	return isFraction;

}



function IsValidChar( ch )

{

	return ( ch == 0 || ch == 1 || ch == 2 || ch == 3 || ch ==4 || ch ==5 || ch ==6 || ch ==7 || ch ==8 || ch ==9 || ch ==" " || ch =="/" );

}



function ParseFraction( frac )

{

	var toReturn;

	var i;

	for( i=0; i < frac.length && frac[i] != " "; i++ );

	

	toReturn =  eval (frac.substr(0, i));

	

	if(i < frac.length - 1) 

		toReturn += eval (frac.substr(i+1, frac.length));

	

	

	return toReturn;

}