//function to change a layer's visibility
function chgVisibility(lyrName, lyrVisibility){

var lyr = eval("document.all." + lyrName + ".style");
var stl = lyrVisibility;

		lyr.visibility = stl;
}


function checkForm(strFormName){

var theForm = "document.forms[\"" + strFormName + "\"]";

var e,i,l,s,r;
var errOccured = false;
theForm = eval(theForm);

	for(i=0;i<theForm.elements.length;i++)
	{
		e = theForm.elements[i];
		if((e.type!='button')&&(e.type!='reset')&&(e.type!='hidden'))
		{
			if(e.attributes['class'].value=='required')
			{
				s = e.value;
				l = new RegExp(" ","gi");
				r = s.replace(l,"");
				if(r=="")
				
				{
				
					alert('You should fill all the required fields');
					errOccured = true;
					break;
				}
			}
		}
	}
	if(!errOccured)
	{
		theForm.submit();
	}
	return;
}