function calc_wall_area()
{	
	var err=0;
	var cnt = document.top_pg.radiobutton.length;	
	if(document.top_pg.length_sqft.value=="")
	{
		// alert('hi');
		alert("Please Enter Length of room");
		err=1;		
		document.top_pg.length_sqft.focus();
		return false;
	}
	if(document.top_pg.length_sqft.value.match(/[ A-Za-z`~!#$%^*()_:;"'|<>?]+/))
	{
		alert("Please Enter Only numeric value for Length of room");
		err=1;		
		document.top_pg.length_sqft.value="";
		document.top_pg.length_sqft.focus();
		return false;
	}	
	
	if(document.top_pg.height_sqft.value=="")
	{
		alert("Please Enter Height of room");
		err=1;		
		document.top_pg.height_sqft.focus();
		return false;
	}
	if(document.top_pg.height_sqft.value.match(/[ A-Za-z`~!#$%^*()_:;"'|<>?]+/))
	{
		alert("Please Enter Only numeric value for Height of room");
		err=1;		
		document.top_pg.height_sqft.value="";
		document.top_pg.height_sqft.focus();
		return false;
	}
	if(cnt==0)
	{
		alert("Still no product Added..");
	}
	else if(cnt > 1)
	{
		var chk=0
		for(var x=0; x<cnt; x++)
		{
			if(document.top_pg.radiobutton[x].checked==true)
			{
				document.top_pg.tilesize.value = document.top_pg.radiobutton[x].value;
				chk=1;
			}
		}
		if(chk==0)
		{
			alert("Please select one of the tiles size");
			err=1;
			document.top_pg.radiobutton[0].focus();
			return false;
		}
	}
	else
	{
		if(document.top_pg.radiobutton.checked==false)
		{
			alert("Please select one of the tiles size");
			err=1;
			document.top_pg.radiobutton.focus();
			return false;			
		}
		else
		{
			document.top_pg.tilesize.value = document.top_pg.radiobutton.value;
		}
	}
	if(err == 0)
	{
		var area_sq_feet = document.top_pg.length_sqft.value * document.top_pg.height_sqft.value;
		if(area_sq_feet < 0)
		{
			alert("Eithers of input is wrong!!");
			document.top_pg.height_sqft.focus();
			return false;			
		}
		// geting size of tiles in sqft
		var splt_size = document.top_pg.tilesize.value.split("~");
		if(splt_size[0] < 0 || splt_size[1] < 0)
		{
			alert("Some error has occurd.. Sorry for incovinance..");
			return false;
		}
		else
		{
			var tile_sqft_length = splt_size[0] * 0.0032808399
			var tile_sqft_height = splt_size[1] * 0.0032808399
			var tile_sqft = tile_sqft_length * tile_sqft_height;
			//alert(tile_sqft)
			
		}
		// # end of geting tiles size		
		var total_tiles_before_waste, total_tiles
		document.top_pg.AreaSqFt.value=area_sq_feet;
		// calculate total number of tiles needed
		total_tiles_before_waste=area_sq_feet / tile_sqft;
		total_waste_add = total_tiles_before_waste * 0.10;
		total_tiles = Math.ceil(total_tiles_before_waste + total_waste_add);
		document.top_pg.NumTile.value=total_tiles;
		var em_tab_txt='<table width="450" border="0" cellpadding="0" cellspacing="0"><tr align="center" valign="top" bgcolor="#FFFFFF"><td height="25" colspan="2" valign="middle"><span class="paratext_head"><font size="2">Wall Tiles Calculator</font></span></td></tr><tr valign="top"><td width="228" height="25" align="left" valign="middle" bgcolor="#FFFFFF" class="paratext"><b>&nbsp;&nbsp;From [Name]:</b></td><td height="25" align="left" valign="middle" class="newstxt"><input name="from_name" type="text" class="form_textfield" id="from_name"></td></tr><tr valign="middle" bgcolor="#FFFFFF"><td height="25" align="left" class="paratext"><b>&nbsp;&nbsp;From [Email]:</b></td><td height="25" align="left"><input name="from_email" type="text" class="form_textfield" id="from_email"></td></tr><tr valign="middle" bgcolor="#FFFFFF"><td height="25" align="left" class="paratext"><b>&nbsp;&nbsp;Architect [Email]:</b></td><td height="25" align="left"><input name="architect_email" type="text" class="form_textfield" id="architect_email"></td></tr><tr valign="top" bgcolor="#FFFFFF"><td height="25" align="left" valign="middle" class="paratext"><b>&nbsp;&nbsp;Other [Email]:</b></td><td height="25" align="left" valign="middle"><input name="other_email" type="text" class="form_textfield" id="other_email"></td></tr><tr align="center" valign="top" bgcolor="#FFFFFF"><td></td><td height="50" align="left" valign="middle" class="paratext"><input type="submit" name="Submit" value="Submit" class="form_btn1"></td></tr></table>';
		document.getElementById("em_tbl").innerHTML = em_tab_txt;		
	}
}