function getImc() { 
var imcLeft = 0, imcCase = 0, src = 'obesite-nutrition/imc/IMC'; 
var imc = Math.ceil ((document.f1.poids.value * 10000) / ( (document.f1.taille.value) * (document.f1.taille.value) )); 
document.f1.imcResult.value = imc; if (imc <= 0) { imcCase = 0; } 
else if (imc <18) {
imcCase= 4; }
else if ((imc >= 18) && (imc <=25)) {
 imcCase = 1; } else if (imc <= 30) {
 imcCase = 2; } else if (imc >30) {
 imcCase = 3; } 

if (imcCase > 0) {
 src += "_" + imcCase;
} 

document.imcImage.src = src + ".gif";
if (imc <= 18) imcLeft = -75; 
if (imc > 35) imcLeft = -330; 
if ((imc > 18) && (imc <= 25)) imcLeft = - ((imc - 18) / 7) * 97 - 85 ; 
if ((imc > 25) && (imc <= 35)) imcLeft = - ((imc - 25) / 5) * 94 - 170 ; 
if (imcCase > 0) { document.imcArrow.style.left = -imcLeft; document.imcArrow.style.visibility = ''; 
} else {
document.imcImage.src = 'obesite-nutrition/imc/IMC.gif'; document.imcArrow.style.visibility = 'hidden'; } 
}