function CalcSqFt(){
 
L1 = document.calculate.length1.value
L2 = document.calculate.length2.value
L3 = document.calculate.length3.value
W1 = document.calculate.width1.value
W2 = document.calculate.width2.value
W3 = document.calculate.width3.value
 
 
if (L1=="" && W1=="" && L2=="" && W2=="" && L3=="" && W3==""){
alert('Enter the length and width of the areas.');
document.calculate.length1.focus;
}
 
if ((L1!="" && isNaN(parseInt(L1))) || (W1!="" && isNaN(parseInt(W1))) || (L2!="" && isNaN(parseInt(L2))) || (W2!="" && isNaN(parseInt(W2))) || (L3!="" && isNaN(parseInt(L3))) || (W3!="" && isNaN(parseInt(W3)))){
alert('Please enter only numerical values.');
document.calculate.length1.focus;
}
 
if (L1!="" && W1!="" && L2=="" && W2=="" && L3=="" && W3==""){
area1 = (L1*W1);
document.calculate.sq_ft.value = area1;
}
else {
if (L1!="" && W1!="" && L2!="" && W2!="" && L3=="" && W3==""){
area1 = (L1*W1);
area2 = (L2*W2);
document.calculate.sq_ft.value = (area1+area2);
}
else {
area1 = (L1*W1);
area2 = (L2*W2);
area3 = (L3*W3);
document.calculate.sq_ft.value = (area1+area2+area3);
}
}
 
needpallets = ((document.calculate.sq_ft.value)/450);
roundpallets = Math.round(needpallets * 100)/100;
document.calculate.pallets.value = roundpallets
 
}