function ValidateData() {

//Submission variable
var CanSubmit = false;

//Check to make sure that the worksheet title field is not empty.
CanSubmit = ForceEntry("WorksheetTitle", "Please enter a title for the worksheet.");
if (!CanSubmit) return;

// check numeric entries are numeric 
CanSubmit = ForceNumber("QuestionCount", "Number of questions");
if (!CanSubmit) return;

CanSubmit = ForceNumber("RangeLower", "Number to generate percentages of (lower range)");
if (!CanSubmit) return;

CanSubmit = ForceNumber("RangeUpper", "Number to generate percentages of (upper range)");
if (!CanSubmit) return;

//Check at least one percentage type has been ticked
if ( (!document.getElementById("1 Percent Checkbox").checked) &&
	(!document.getElementById("5 Percent Checkbox").checked) &&
	(!document.getElementById("10 Percent Checkbox").checked) &&
	(!document.getElementById("25 Percent Checkbox").checked) &&
	(!document.getElementById("100 Percent Checkbox").checked) &&
	(!document.getElementById("Use Specified Percent Checkbox").checked) )
	{
		alert("Please select at least one percentage type from the\n'percentages to calculate' list.");	
		return;
	}

//If a specified percentage has been selected, check there is a value in the
//specified percent textbox
if	(document.getElementById("Use Specified Percent Checkbox").checked) 
	{
		CanSubmit = ForceNumber("SpecifiedPercent", "Please enter a specified percent to use.");		
		if (!CanSubmit) return;
	}
	
//Check at least one question type has been ticked
if ( (!document.getElementById("Qof Checkbox").checked) &&
	(!document.getElementById("Qmore Checkbox").checked) &&
	(!document.getElementById("Qless Checkbox").checked) )
	{
		alert("Please select at least one question type from the\n'question format' list.");	
		return;
	}
	
CanSubmit = ForceNumber("PercentRangeLower", "Percentage (lower range)");
if (!CanSubmit) return;

CanSubmit = ForceNumber("PercentRangeUpper", "Percentage (upper range)");
if (!CanSubmit) return;
		

// check question range
if (parseInt(document.getElementById("QuestionCount").value) < 1 || parseInt(document.getElementById("QuestionCount").value) > 99)  
  { 
  alert ("Please enter a value in the 'number of questions' box between 1 and 99."); 
  CanSubmit = false;
  return; 
  } 

//If fields have been entered correctly, submit the form
if (CanSubmit) document.LayoutPercentage.submit();

} //end function